Tris(pentane-2,4-dionato-O,O')vanadium

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2002

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

short-term repeated dose toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1990/04/10 - 1990/04/27

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 412 (Subacute Inhalation Toxicity: 28-Day Study)

Version / remarks:

test duration of 16 days

Deviations:

yes

Remarks:

no haematology and clinical biochemistry examination

GLP compliance:

not specified

Limit test:

no

Specific details on test material used for the study:

Vanadium pentoxide was obtained from Shieldalloy Metallurgical Corporation (Newfield, NJ). Lot 1210490 was used in the 16-day and 3 months studies. Lot 1210490, an orange, crystalline solid, was identified as vanadium pentoxide by the analytical chemistry laboratory using X-ray diffraction (XRD) analyses and infrared and ultraviolet/visible spectroscopy and by the study laboratory using infrared spectroscopy. Infrared spectra were consistent between the lots used in different studies and with the structure of vanadium pentoxide (Nyquist and Kagel, 1971). XRD analyses of both lots indicated the presence of vanadium pentoxide with no detectable contaminants.

Species:

other: Male and female F344/N rats and B6C3F1 mice

Strain:

other: Male and female F344/N rats and B6C3F1 mice

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Simonsen Laboratories (Gilroy, CA)
- Age at study initiation: 6 weeks
- Weight at study initiation: male rat 122 - 126 g, female rat 101 - 104 g (range of means of 5 groups); male mice 23.4 - 23.7 g female mice 18.2 - 19.5 g (range of means of 5 groups)
- Housing: rats and mice were housed individually in stainless steel wire mesh cages
- Diet (e.g. ad libitum): ad libitum, except during exposure periods
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 12-13 d

DETAILS OF FOOD AND WATER QUALITY:
Diet: NIH-07 open formula pelleted diet (Zeigler Brothers, Inc., Gardners, PA), available ad libitum except during exposure periods changed weekly
Water: Tap water (City of Chicago municipal supply) via automatic watering system (Edstrom Industries, Waterford, WI), available ad libitum, changed weekly

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23.9°C
- Humidity (%): 55 % +- 15 %
- Air changes (per hr): 15 air changes/hour
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Vehicle:

air

Mass median aerodynamic diameter (MMAD):

>= 1 - <= 1.3 µm

Geometric standard deviation (GSD):

2.8

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Aerosol leaving the jetmill passed through a one-stage impactor and a vertical elutriator to eliminate or deagglomerate the large particles before entering a plenum and manifold distribution system. The aerosol delivery system consisted of three holding chambers that diluted the aerosol in three stages. A metered amount of diluted aerosol was removed and mixed with conditioned air at the inlet to each exposure chamber to achieve the appropriate exposure concentration. The electrical charge buildup on the aerosol particles was neutralized by mixing the aerosol with high concentrations of bipolar ions, which were generated using a Pulse Gun (Static Control Services, Palm Springs, CA) air nozzle.
- Method of holding animals in test chamber: not specified
- Source and rate of air: not specified
- Method of conditioning air: Chamber Air Supply Filters HEPA (R&R Equipment Sales, Rosemont, IL)
- System of generating particulates/aerosols: Vanadium pentoxide aerosol generation was based on the principle of pneumatic dispersion and consisted of two major components: a screw feeder (Model 310, Accurate, White Water, WI) that metered vanadium pentoxide powder at a constant rate and a Jet-O-Mizer jetmill (Fluid Energy Corp., Harfield, PA) that used compressed air to disperse the metered powder and form the aerosol
- Temperature, humidity, pressure in air chamber: 23.9°C, 55 +- 15 % humidity
- Air flow rate: 15 air changes/hour
- Air change rate: 15 air changes/hour
- Method of particle size determination: The particle size distribution in each chamber was determined prior to the start of all studies, during the first week of the 16-day study. A 10-stage Quartz Crystal Microbalance-based cascade impactor (California Measurements, Inc., Sierra Madre, CA) was used to separate the aerosol particles into sequential size ranges; the mass median aerodynamic diameter was calculated from the corresponding mass fraction of particles at each stage.
- Treatment of exhaust air: not specified

TEST ATMOSPHERE
- Brief description of analytical method used: During all studies, chamber aerosol concentrations were monitored with real-time aerosol monitors (RAMs) that used a pulsed-light-emitting diode in combination with a silicon detector to sense light scattered over a forward angular range of 45° to 95° by particles traversing the sensing volume. The instruments respond to particles 0.1 to 20 μm in diameter.
- Samples taken from breathing zone: yes, an individual monitor was used for each exposure chamber

VEHICLE (if applicable)
- Justification for use and choice of vehicle: no details given
- Composition of vehicle: conditioned air
- Concentration of test material in vehicle: 0, 2, 4, 8, 16, or 32 mg/m3
- Purity of vehicle: not specified

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The uniformity of aerosol concentration in the inhalation exposure chambers without animals was evaluated before each of the studies began; concentration uniformity with animals present in the chambers was also measured once during the 16-day studies. During the 16-day and 3-month studies, minor excursions in chamber uniformity values (between-port and within-port variability) were observed in one or more exposure chambers, but these excursions had no impact on the studies.

Duration of treatment / exposure:

6 hours plus T90 (15 minutes) per day

Frequency of treatment:

5 days per week for 16 days.

Dose / conc.:

0 mg/m³ air

Remarks:

dose for core and immunotoxicology study

Dose / conc.:

2 mg/m³ air

Remarks:

dose for core study

Dose / conc.:

4 mg/m³ air

Remarks:

dose for core and immunotoxicology study

Dose / conc.:

8 mg/m³ air

Remarks:

dose for core study

Dose / conc.:

16 mg/m³ air

Remarks:

dose for core and immunotoxicology study

Dose / conc.:

32 mg/m³ air

Remarks:

dose for core study

No. of animals per sex per dose:

5 male and 5 female rats (core study), 22 male rats and 50 female mice designated (immunotoxicology study)

Control animals:

yes, concurrent vehicle

Details on study design:

- Rationale for animal assignment (if not random): Animals were distributed randomly into groups of approximately equal initial mean body weights.

Positive control:

no positive control

Observations and examinations performed and frequency:

Clinical findings were recorded daily. Core study animals were weighed initially, on day 7, and at the end of the studies; immunotoxicology study animals were weighed initially and at the end of the studies.

Sacrifice and pathology:

Method of Sacrifice: CO2 asphyxiation
Necropsies were performed on all core study rats and mice. The heart, right kidney, liver, lung, right testis, and thymus of core study animals were weighed. Histopathologic examinations were performed on all organs from exposed animals that showed evidence of gross lesions along with corresponding organs of all chamber control animals.

Statistics:

Survival Analyses
The probability of survival was estimated by the product-limit procedure of Kaplan and Meier (1958). Statistical analyses for possible doserelated effects on survival used Cox’s (1972) method for testing two groups for equality and Tarone’s (1975) life table test to identify dose-related trends. All reported P values for the survival analyses are two sided.

Analysis of Continuous Variables
Two approaches were employed to assess the significance of pairwise comparisons between exposed and control groups in the analysis of continuous variables. Organ and body weight data, which historically have approximately normal distributions, were analyzed with the parametric multiple comparison procedures of Dunnett (1955) and Williams (1971, 1972). Hematology, clinical chemistry, urinalysis, urine concentrating ability, cardiopulmonary, immunotoxicologic, cell proliferation, tissue concentrations, spermatid, and epididymal spermatozoal data, which have typically skewed distributions, were analyzed using the nonparametric multiple comparison methods of Shirley (1977) and Dunn (1964).

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

rats: During the first week of the study, red nasal discharge, rapid respiration, and hypoactivity were observed in all 32 mg/m3 rats; rapid respiration was also observed in all rats exposed to 16 mg/m3. Rapid, shallow respiration was most visible during exposure periods but persisted immediately following exposure. From day 8 until the end of the study, rats in the 32 mg/m3 groups became emaciated and had hunched and/or abnormal posture and a rough coat; one of the two surviving males had labored breathing.
mice: Hypoactivity was observed in the 32 mg/m3 groups; one of the affected females also had labored breathing. Some males in the 32 mg/m3 groups had hunched posture, and one was emaciated.

Mortality:

mortality observed, treatment-related

Description (incidence):

rats: Three males exposed to 32 mg/m3 died before the end of the study
mice: All males exposed to 32 mg/m3 died or were killed moribund and one male exposed to 8 mg/m3 died before the end of the study

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

rats: Final mean body weights and body weight gains of males and females exposed to 8 mg/m3 or greater were less than those of the chamber controls.
mice: Final mean body weights and body weight gains of 16 mg/m3 males and 32 mg/m3 females were significantly less than those of the chamber controls; 32 mg/m3 females lost weight during the study. Additionally, final mean body weights of 8 and 16 mg/m3 females were significantly less than those of the chamber controls.

Food efficiency:

not specified

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

effects observed, treatment-related

Description (incidence and severity):

rats: Urine staining was observed in 32 mg/m3 females

Immunological findings:

no effects observed

Description (incidence and severity):

rats and mice (immunotoxicology study): There were no effects on systemic immunity, evidenced by a normal response to Klebsiella pneumoniae. Other measures of immune function were not considered to be significantly different than those of the chamber controls.

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

rats: Relative lung weights of 4 mg/m3 or greater males and 2 mg/m3 or greater females were significantly greater than those of the chamber controls. Other organ weight differences were considered to be related to body weight decreases.
mice: Absolute and relative lung weights of 4 mg/m3 or greater males and all exposed groups of females were significantly greater than those of the chamber controls. In addition, liver weights of 16 mg/m3 males were significantly greater. Other organ weight differences were considered to be related to body weight decreases.

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

rats: Gross lesions observed at necropsy were not considered to be exposure related. Complete histopathology was not performed.
mice: Thymus weights were similar to those of the chamber controls in all exposed groups except 32 mg/m3 females. Mediastinal lymph nodes of several males and females exposed to 2 (females only), 4, 8, or 16 mg/m3 were enlarged.

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

rats: A localized inflammatory response in the lung was evident in male rats based on increases in cell number, protein, neutrophils, and lysozymes in lavage fluid in all exposed groups. There was also a significant decrease in macrophages in lavage fluids of male rats exposed to 8 or 16 mg/m3.
mice: A localized inflammatory response in the lung was evident based on increases in cell number, protein, lymphocytes, neutrophils, and lysozymes in lavage fluid. There was also a significant decrease in macrophages in lavage fluid.

Histopathological findings: neoplastic:

no effects observed

Other effects:

effects observed, treatment-related

Description (incidence and severity):

rats: Salivation, and diarrhea were observed in 32 mg/m3 females. Ocular or nasal discharge was noted in the 16 mg/m3 groups.

Dose descriptor:

conc. level: body weight deficit > 10 %

Remarks:

rats

Effect level:

16 mg/m³ air

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

Dose descriptor:

conc. level: 32

Remarks:

rats and mice

Effect level:

32 mg/m³ air

Based on:

test mat.

Sex:

male

Basis for effect level:

mortality

Critical effects observed:

no

Conclusions:

In the 16-day studies, mortality occurred in male rats and mice exposed to 32 mg/m3, and body weight deficits greater than 10% were observed in male and female rats exposed to concentrations of 16 mg/m3 or greater and in 32 mg/m3 mice.

Executive summary:

Rats

Groups of five male and five female rats were exposed to particulate aerosols of vanadium pentoxide at concentrations of 0, 2, 4, 8, 16, or 32 mg/m3 by inhalation, 6 hours per day, 5 days per week for 16 days. Three males in the 32 mg/m3 group died before the end of the study. Mean body weights of males and females exposed to 8 mg/m3 or greater were less than those of the chamber controls. Clinical findings included rapid respiration and hypoactivity in rats exposed to 16 or 32 mg/m3. Relative lung weights of 4 mg/m3 or greater males and 2 mg/m3 or greater females were significantly greater than those of the chamber controls. Lavage fluid analysis indicated an inflammatory response in the lung that was either directly mediated by vanadium pentoxide or was secondary to lung damage induced by vanadium pentoxide exposure.

Mice

Groups of five male and five female mice were exposed to particulate aerosols of vanadium pentoxide at concentrations of 0, 2, 4, 8, 16, or 32 mg/m3 by inhalation, 6 hours per day, 5 days per week for 16 days. All males exposed to 32 mg/m3 and one 8 mg/m3 male died or were killed moribund before the end of the study. Mean body weights of 16 mg/m3 males and 8 mg/m3 or greater females were significantly less than those of the chamber controls, and the 32 mg/m3 females lost weight during the study. Absolute and relative lung weights of 4 mg/m3 or greater males and all exposed groups of females and liver weights of 16 mg/m3 males were significantly greater than those of the chamber controls. The mediastinal lymph nodes were enlarged in 4, 8, and 16 mg/m3 males and females, and lymphoid hyperplasia was confirmed histologically. Lavage fluid analysis indicated an inflammatory response in the lung that was either directly mediated by vanadium pentoxide or was secondary to lung damage induced by vanadium pentoxide exposure.

Cross-reference 2

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

chronic toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1997/01/06 - 1999/01/15

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 453 (Combined Chronic Toxicity / Carcinogenicity Studies)

Version / remarks:

route of exposure: inhalation

Deviations:

yes

Remarks:

animals were not weighed weekly for the first 13 weeks, but every 4 weeks; no haematology and clinical biochemistry examined, no urinanalysis

GLP compliance:

yes

Remarks:

The 3-month and 2-year studies were conducted in compliance with Food and Drug Administration Good Laboratory Practice Regulations (21 CFR, Part 58).

Specific details on test material used for the study:

Vanadium pentoxide was obtained from Shieldalloy Metallurgical Corporation (Newfield, NJ). Lot 1210140 was used in the 16-day special studies and the 2-year studies. Lot 1210140, a light orange, crystalline solid, was identified by the analytical chemistry laboratory using infrared and ultraviolet/visible spectroscopy and by the the study laboratory using XRD analysis. Infrared spectra were consistent between lots used in different studies and with the structure of vanadium pentoxide (Nyquist and Kagel, 1971). XRD analyses indicated the presence of vanadium pentoxide with no detectable contaminants.

Species:

other: Male and female F344/N rats and B6C3F1 mice

Strain:

other: Male and female F344/N rats and B6C3F1 mice

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Taconic Farms, Inc. (Germantown, NY)
- Age at study initiation: 6 to 7 weeks
- Weight at study initiation: not specified
- Fasting period before study: no
- Housing: rats and mice were housed individually in stainless steel wire mesh (Lab Products, Inc., Maywood, NJ), Cages and racks were rotated weekly
- Diet (e.g. ad libitum): ad libitum except during exposure periods
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 16 d (mice), 19 d (rat)

DETAILS OF FOOD AND WATER QUALITY:
Diet: NIH-07 open formula pelleted diet (Zeigler Brothers, Inc., Gardners, PA), available ad libitum except during exposure periods changed weekly
Water: Tap water (City of Chicago municipal supply) via automatic watering system (Edstrom Industries, Waterford, WI), available ad libitum, changed weekly

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23.9°C
- Humidity (%): 55 % +- 15 %
- Air changes (per hr): 15 air changes/hour
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Vehicle:

air

Mass median aerodynamic diameter (MMAD):

>= 1 - <= 1.6 µm

Geometric standard deviation (GSD):

2

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: The stainless-steel inhalation exposure chambers (Harford Systems Division of Lab Products, Inc., Aberdeen, MD) were designed so that uniform aerosol concentrations could be maintained throughout the chambers when catch pans were in place. The total active mixing volume of each chamber was 1.7 m3.
- Method of holding animals in test chamber: mot specified
- Source and rate of air: not specified
- Method of conditioning air: Chamber Air Supply Filters HEPA (R&R Equipment Sales, Rosemont, IL)
- System of generating particulates/aerosols: The generation and delivery system used in the 2-year studies consisted of a linear dust feeder, a particle attrition chamber, and an aerosol distribution system. The linear dust feeder, a slide-bar dust-metering device, was composed of a shuttle bar, body, outlet port, and hopper.
- Temperature, humidity, pressure in air chamber: 23.9°C, 55 +- 15 % humidity
- Air flow rate: 15 changes/hour
- Air change rate: 15 changes/hour
- Method of particle size determination: The particle size distribution in each chamber was determined prior to the start of the study, during the first 2 weeks and monthly. A Mercer-style seven-stage impactor (In-Tox Products, Albuquerque, NM) was used to separate the aerosol particles into sequential size ranges; the mass median aerodynamic diameter was calculated from the corresponding mass fraction of particles at each stage. The stages (glass coverslips lightly sprayed with silicon) were analyzed by ICP/AES, and the relative mass collected on each stage was analyzed by probit analysis.
- Treatment of exhaust air: not specified

TEST ATMOSPHERE
- Brief description of analytical method used: During all studies, chamber aerosol concentrations were monitored with real-time aerosol monitors (RAMs) that used a pulsed-light-emitting diode in combination with a silicon detector to sense light scattered over a forward angular range of 45° to 95° by particles traversing the sensing volume. The instruments respond to particles 0.1 to 20 μm in diameter.
- Samples taken from breathing zone: yes, an individual monitor was used for each exposure chamber

VEHICLE (if applicable)
- Justification for use and choice of vehicle: no details given
- Composition of vehicle: conditioned air
- Concentration of test material in vehicle: 0.5, 1, and 2 mg/m3 (rats); 1, 2, and 4 mg/m3 (mice)
- Purity of vehicle: not specified

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The uniformity of aerosol concentration in the inhalation exposure chambers without animals was evaluated before each of the studies began; concentration uniformity with animals present in the chambers was also measured every 3 months during the 2-year studies. RAM measurements were taken from 12 different chamber positions. Chamber concentration uniformity was acceptable throughout the study.

Duration of treatment / exposure:

6 hours plus T90 (12 minutes) per day

Frequency of treatment:

5 days per week for 104 weeks

Dose / conc.:

0 mg/m³ air

Remarks:

rats and mice

Dose / conc.:

0.5 mg/m³ air

Remarks:

rats

Dose / conc.:

1 mg/m³ air

Remarks:

rats and mice

Dose / conc.:

2 mg/m³ air

Remarks:

rats and mice

Dose / conc.:

4 mg/m³ air

Remarks:

mice

No. of animals per sex per dose:

Core studies: 50 male and 50 female rats and mice
Tissue burden studies: 40 female rats and mice; 15 female rats and mice (chamber control)

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale:
rats: Based on the incidences and severities of respiratory lesions and increased lung weights in male and female rats, concentrations of 4 mg/m3 or greater were considered to be too high for use in a 2-year study. The exposure concentrations selected for the 2-year inhalation study in rats were 0.5, 1, and 2 mg/m3.
mice: Based on reduced body weight gain of 8 and 16 mg/m3 males and females and increased incidences of inflammation and epithelial hyperplasia of the lung in 8 and 16 mg/m3 males and females, exposure concentrations greater than 4 mg/m3 were considered too high for use in a 2-year study. The exposure concentrations selected for the 2-year inhalation study in mice were 1, 2, and 4 mg/m3.
- Rationale for animal assignment (if not random): Animals were distributed randomly into groups of approximately equal initial mean body weights.

Positive control:

no positive control

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: every 4 weeks from week 5 through 89 and every 2 weeks from week 92 until the end of the studies.

BODY WEIGHT: Yes
- Time schedule for examinations: day 1 and every 4 weeks from week 5 through 89 and every 2 weeks from week 92 until the end of the studies.

HAEMATOLOGY: No

CLINICAL CHEMISTRY: No

URINALYSIS: No

Sacrifice and pathology:

Sacrifice via CO2 asphyxiation

Necropsy was performed on all core study animals.

Complete histopathology was performed on all core study animals. In addition to gross lesions and tissue masses, the following tissues were examined: adrenal gland, bone with marrow, brain, clitoral gland, esophagus, gallbladder (mice only), heart and aorta, large intestine (cecum, colon, and rectum), small intestine (duodenum, jejunum, and ileum), kidney, larynx, liver, lung and mainstem bronchi, lymph nodes (mandibular, mediastinal, mesenteric, and bronchial), mammary gland (except male mice), nose, ovary, pancreas, parathyroid gland, pituitary gland, preputial gland, prostate gland, salivary gland, skin, spleen, stomach (forestomach and glandular), testis (with epididymis and seminal vesicle), thymus, thyroid gland, trachea, urinary bladder, and uterus

Statistics:

Survival Analyses
The probability of survival was estimated by the product-limit procedure of Kaplan and Meier (1958). Statistical analyses for possible doserelated effects on survival used Cox’s (1972) method for testing two groups for equality and Tarone’s (1975) life table test to identify dose-related trends. All reported P values for the survival analyses are two sided.

Analysis of Continuous Variables
Two approaches were employed to assess the significance of pairwise comparisons between exposed and control groups in the analysis of continuous variables. Organ and body weight data, which historically have approximately normal distributions, were analyzed with the parametric multiple comparison procedures of Dunnett (1955) and Williams (1971, 1972). Hematology, clinical chemistry, urinalysis, urine concentrating ability, cardiopulmonary, immunotoxicologic, cell proliferation, tissue concentrations, spermatid, and epididymal spermatozoal data, which have typically skewed distributions, were analyzed using the nonparametric multiple comparison methods of Shirley (1977) and Dunn (1964).

The Poly-k test (Bailer and Portier, 1988; Portier and Bailer, 1989; Piegorsch and Bailer, 1997) was used to assess neoplasm and nonneoplastic lesion prevalence.

Clinical signs:

effects observed, non-treatment-related

Description (incidence and severity):

rats: No clinical findings related to vanadium pentoxide exposure were observed.
mice: Many animals exposed to vanadium pentoxide were thin, and abnormal breathing was observed in some animals, particularly those exposed to 2 or 4 mg/m3 vanadium pentoxide.

Mortality:

mortality observed, treatment-related

Description (incidence):

rats: Survival of exposed males and females was similar to that of the chamber controls.
mice: Survival of males exposed to 4 mg/m3 was significantly less than that of the chamber controls.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

rats: Mean body weights of females exposed to 2 mg/m3 were marginally less than those of the chamber controls throughout the 2-year study; mean body weights of exposed and chamber control males were similar throughout the study
mice: Mean body weights of males exposed to 4 mg/m3 and all exposed groups of females were generally less than those of the chamber controls throughout the study, and mean body weights of males exposed to 2 mg/m3 were less from week 85 to the end of the study.

Food efficiency:

not examined

Ophthalmological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

rat (Tissue burden analysis): Lung weights from exposed female rats increased throughout the study

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

Statistically significant or biologically noteworthy changes in the incidences of neoplasms and nonneoplastic lesions of the lung, larynx, nose, uterus, and kidney were observed (please refer to 'Details on results').

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Statistically significant or biologically noteworthy changes in the incidences of neoplasms and nonneoplastic lesions of the lung, larynx, nose, uterus, and kidney were observed (please refer to 'Details on results').

Histopathological findings: neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Statistically significant or biologically noteworthy changes in the incidences of neoplasms and nonneoplastic lesions of the lung, larynx, nose, uterus, and kidney were observed (please refer to 'Details on results').

Details on results:

RATS
Lung: Although there were no statistically significant increases in the incidences of lung neoplasms in rats, the incidences of alveolar/bronchiolar adenoma in 0.5 mg/m3 males and of alveolar/bronchiolar carcinoma and alveolar/bronchiolar adenoma or carcinoma (combined) in 0.5 and 2 mg/m3 males exceeded the historical ranges in controls (all routes) given NTP-2000 diet and in inhalation chamber controls given NIH-07 diet. This response was considered related to exposure to vanadium pentoxide.
Larynx: There were increased incidences of minimal to mild lesions of the larynx in males and females exposed to vanadium pentoxide. The incidences generally increased with increasing exposure concentration and included chronic inflammation of the larynx and degeneration, hyperplasia, and squamous metaplasia of the respiratory epithelium of the epiglottis.
Uterus: The incidences of stromal polyp occurred with a positive trend in female rats (chamber control, 6/50; 0.5 mg/m3, 3/50; 1 mg/m3, 7/50; 2 mg/m3, 13/50)
Kidney: The incidences of nephropathy (37/50, 42/50, 46/49, 47/50) were significantly increased in male rats exposed to 1 or 2 mg/m3. Nephropathy is a common lesion in aged rats

MICE
Lung: The incidences of alveolar/bronchiolar carcinoma and alveolar/bronchiolar adenoma or carcinoma (combined) were significantly increased in all groups of exposed male and female mice. The incidences of alveolar/bronchiolar adenoma were significantly increased in males exposed to 2 mg/m3 and in all groups of exposed females.
Larynx: There were significantly increased incidences of minimal squamous metaplasia of the respiratory epithelium of the epiglottis in exposed groups
Nose: There were increased incidences of minimal to mild suppurative inflammation of the nose in males and females exposed to 2 or 4 mg/m3. The majority of the olfactory epithelium covers the turbinates in the distal portion of the nose. There were marginal but significant increases in the incidences of atrophy of this epithelium in females exposed to 1 or 4 mg/m3, and the incidences in exposed males, though not significant, occurred with a positive trend.
Bronchial Lymph Node: There were significant increases in the incidences of hyperplasia of the bronchial lymph node in exposed groups of females, and while not significant, a positive trend in the incidences of this lesion also occurred in males.
Spleen: There was a positive trend in the incidences of hemangiosarcoma of the spleen in male mice (chamber control, 0/50; 1 mg/m3, 0/50; 2 mg/m3, 0/50; 4 mg/m3, 3/50.
Other Organs: There was a significant decrease in the incidence of harderian gland adenoma in male mice exposed to 4 mg/m3; however, the incidence of harderian gland adenoma or carcinoma (combined) in this group was not statistically significant. Negative trends in the incidences of hepatocellular adenoma and hepatocellular adenoma or carcinoma (combined) occurred in males.

Dose descriptor:

conc. level: increased mortality

Remarks:

mice

Effect level:

4 mg/m³ air

Based on:

test mat.

Sex:

male/female

Basis for effect level:

mortality

Dose descriptor:

conc. level: body weight deficits

Remarks:

mice

Effect level:

1 mg/m³ air

Based on:

test mat.

Sex:

female

Basis for effect level:

body weight and weight gain

Dose descriptor:

conc. level: abnormal breathing

Remarks:

mice

Effect level:

2 mg/m³ air

Based on:

test mat.

Sex:

male/female

Basis for effect level:

clinical signs

Dose descriptor:

conc. level: body weight deficits

Remarks:

rats

Effect level:

2 mg/m³ air

Based on:

test mat.

Sex:

female

Basis for effect level:

body weight and weight gain

Dose descriptor:

LOAEL

Remarks:

rats

Effect level:

0.5 mg/m³ air

Based on:

test mat.

Sex:

female

Basis for effect level:

histopathology: neoplastic

Dose descriptor:

conc. level: alveolar/bronchiolar adenomas

Remarks:

mice

Effect level:

2 mg/m³ air

Based on:

test mat.

Sex:

male

Basis for effect level:

histopathology: neoplastic

Dose descriptor:

conc. level: alveolar/bronchiolar adenomas

Remarks:

mice

Effect level:

1 mg/m³ air

Based on:

test mat.

Sex:

female

Basis for effect level:

histopathology: neoplastic

Critical effects observed:

yes

Lowest effective dose / conc.:

0.5 mg/m³ air

System:

respiratory system: lower respiratory tract

Organ:

alveoli

bronchi

bronchioles

lungs

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Tissue Burden Analyses

Tissue burden analyses were performed on female rats exposed to 0.5, 1, or 2 mg/m3 on days 1, 5, 12, 26, 54, 173, 360, and 540. Lung weights from exposed female rats increased throughout the study.

Various tests used to determine if lung burdens were proportional to exposure concentration gave contradictory results. Simple visual inspection of the lung burden data indicates that lung burdens increased roughly in proportion to exposure concentration. Lung burdens normalized to exposure concentration would be expected to remain constant across all exposure concentrations if the toxicokinetics were linear. Although proportionality may not have been evident when examined at several individual time points, departures from proportional behavior were small. However, when lung burden data were integrated over all time points, they did appear to be approximately proportional to exposure concentration.

Though deposition patterns were similar between rats and mice, the maximum lung burdens occurred much later in rats (day 173) than in mice (days 26 to 54). The lung burdens appeared to reach steady state at the lowest exposure concentrations in rats (0.5 mg/m3) and mice (1 mg/m3). A decline in lung burdens was observed in both species. It is possible that the decreased deposition rates in rats exposed to 1 mg/m3 or greater and mice exposed to 2 mg/m3 or greater were due to a change in pulmonary function brought about by vanadium pentoxide-induced alterations in the airways and alveoli of the lung as was observed in the 3-month rat studies. The retention of vanadium in the lungs at 18 months was lower in mice (2% to 3%) than in rats (13% to 15%) at comparable exposure concentrations.

From the lung burden studies, the total lung “dose” was estimated for each exposure concentration to aid in interpretation of lung pathology in exposed rats and mice. The total lung doses for rats exposed to 0.5, 1, or 2 mg/m3 were estimated to be 130, 175, and 308 μg vanadium, respectively. The total lung doses for mice exposed to 1, 2, or 4 mg/m3 were 153, 162, and 225 μg vanadium, respectively. There was little difference in the total lung dose for mice, especially between the 1 and 2 mg/m3 groups.

Conclusions:

Under the conditions of this 2-year inhalation study, there was some evidence of carcinogenic activity* of vanadium pentoxide in male F344/N rats and equivocal evidence of carcinogenic activity* of vanadium pentoxide in female F344/N rats based on the occurrence of alveolar/bronchiolar neoplasms. There was clear evidence of carcinogenic activity* of vanadium pentoxide in male and female B6C3F1 mice based on increased incidences of alveolar/bronchiolar neoplasms.
Exposure to vanadium pentoxide caused a spectrum of nonneoplastic lesions in the respiratory tract (nose, larynx, and lung) including alveolar and bronchiolar epithelium hyperplasia, inflammation, fibrosis, and alveolar histiocytosis of the lung in male and female rats and mice and an unusual squamous metaplasia of the lung in male and female rats. Hyperplasia of the bronchial lymph node occurred in female mice.

(*) -Clear evidence of carcinogenic activity is demonstrated by studies that are interpreted as showing a dose-related (i) increase of malignant neoplasms, (ii) increase of a combination of malignant and benign neoplasms, or (iii) marked increase of benign neoplasms if there is an indication from this or other studies of the ability of such tumors to progress to malignancy.
-Some evidence of carcinogenic activity is demonstrated by studies that are interpreted as showing a chemical-related increased incidence of neoplasms (malignant, benign, or combined) in which the strength of the response is less than that required for clear evidence.
-Equivocal evidence of carcinogenic activity is demonstrated by studies that are interpreted as showing a marginal increase of neoplasms that may be chemical related.
-No evidence of carcinogenic activity is demonstrated by studies that are interpreted as showing no chemical-related increases in malignant or benign neoplasms.
-Inadequate study of carcinogenic activity is demonstrated by studies that, because of major qualitative or quantitative limitations, cannot be interpreted as valid for showing either the presence or absence of carcinogenic activity.

Executive summary:

rats

Groups of 50 male and 50 female rats were exposed to particulate aerosols of vanadium pentoxide at concentrations of 0, 0.5, 1, or 2 mg/m3 by inhalation, 6 hours per day, 5 days per week for 104 weeks. Survival and body weights of males and females were generally similar to those of the chamber controls. Mean body weights of females exposed to 2 mg/m3 were less than those of the chamber controls throughout the study. Alveolar/bronchiolar neoplasms were present in exposed groups of male rats, and the incidences often exceeded the historical control ranges. Alveolar/bronchiolar adenomas were present in 0.5 and 1 mg/m3 females; one 2 mg/m3 female also had an alveolar/bronchiolar carcinoma. The incidence of alveolar/bronchiolar adenoma in the 0.5 mg/m3 group was at the upper end of the historical control ranges. Nonneoplastic lesions related to vanadium pentoxide exposure occurred in the respiratory system (lung, larynx, and nose) of male and female rats, and the severities of these lesions generally increased with increasing exposure concentration.

mice

Groups of 50 male and 50 female mice were exposed to particulate aerosols of vanadium pentoxide at concentrations of 0, 1, 2, or 4 mg/m3 by inhalation, 6 hours per day, 5 days per week for 104 weeks. Survival of 4 mg/m3 males was significantly less than that of the chamber controls. Mean body weights of 4 mg/m3 males and all exposed groups of females were generally less than those of the chamber controls throughout the study, and those of males exposed to 2 mg/m3 were less from week 85 to the end of the study. Many mice exposed to vanadium pentoxide were thin, and abnormal breathing was observed in some mice, particularly those exposed to 2 or 4 mg/m3.

The incidences of alveolar/bronchiolar neoplasms were significantly increased in all groups of exposed males and females. Nonneoplastic lesions related to vanadium pentoxide exposure occurred in the respiratory system (lung, larynx, and nose) of male and female mice, and the severities of these lesions generally increased with increasing exposure concentration. Bronchial lymph node hyperplasia was present in many exposed females.

Carcinogenicity

Under the conditions of this 2-year inhalation study, there was some evidence of carcinogenic activity* of vanadium pentoxide in male F344/N rats and equivocal evidence of carcinogenic activity* of vanadium pentoxide in female F344/N rats based on the occurrence of alveolar/bronchiolar neoplasms. There was clear evidence of carcinogenic activity* of vanadium pentoxide in male and female B6C3F1 mice based on increased incidences of alveolar/bronchiolar neoplasms.

Exposure to vanadium pentoxide caused a spectrum of nonneoplastic lesions in the respiratory tract (nose, larynx, and lung) including alveolar and bronchiolar epithelium hyperplasia, inflammation, fibrosis, and alveolar histiocytosis of the lung in male and female rats and mice and an unusual squamous metaplasia of the lung in male and female rats. Hyperplasia of the bronchial lymph node occurred in female mice.

(*) -Clear evidence of carcinogenic activity is demonstrated by studies that are interpreted as showing a dose-related (i) increase of malignant neoplasms, (ii) increase of a combination of malignant and benign neoplasms, or (iii) marked increase of benign neoplasms if there is an indication from this or other studies of the ability of such tumors to progress to malignancy.

-Some evidence of carcinogenic activity is demonstrated by studies that are interpreted as showing a chemical-related increased incidence of neoplasms (malignant, benign, or combined) in which the strength of the response is less than that required for clear evidence.

-Equivocal evidence of carcinogenic activity is demonstrated by studies that are interpreted as showing a marginal increase of neoplasms that may be chemical related.

-No evidence of carcinogenic activity is demonstrated by studies that are interpreted as showing no chemical-related increases in malignant or benign neoplasms.

-Inadequate study of carcinogenic activity is demonstrated by studies that, because of major qualitative or quantitative limitations, cannot be interpreted as valid for showing either the presence or absence of carcinogenic activity.

Cross-reference 3

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1990/09/18 - 1990/12/20

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)

Deviations:

yes

Remarks:

No ophthalmological examination

GLP compliance:

yes

Remarks:

The 3-month and 2-year studies were conducted in compliance with Food and Drug Administration Good Laboratory Practice Regulations (21 CFR, Part 58).

Limit test:

no

Specific details on test material used for the study:

Vanadium pentoxide was obtained from Shieldalloy Metallurgical Corporation (Newfield, NJ). Lot 1210490 was used in the 16-day and 3 months studies. Lot 1210490, an orange, crystalline solid, was identified as vanadium pentoxide by the analytical chemistry laboratory using X-ray diffraction (XRD) analyses and infrared and ultraviolet/visible spectroscopy and by the study laboratory using infrared spectroscopy. Infrared spectra were consistent between the lots used in different studies and with the structure of vanadium pentoxide (Nyquist and Kagel, 1971). XRD analyses of both lots indicated the presence of vanadium pentoxide with no detectable contaminants.

Species:

other: Male and female F344/N rats and B6C3F1 mice

Strain:

other: Male and female F344/N rats and B6C3F1 mice

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Taconic Farms, Inc. (Germantown, NY)
- Age at study initiation: 6 or 7 weeks
- Weight at study initiation: male rat 133 - 137 g, female rat 108 - 111 g (range of means of 5 groups); male mice 25.2 - 26.4 g female mice 19.8 - 21.4 g (range of means of 5 groups)
- Housing: rats and mice were housed individually in stainless steel wire mesh (Lab Products, Inc., Maywood, NJ), changed weekly
- Diet (e.g. ad libitum): ad libitum, except during exposure periods. Feed was also withheld during urine collection
- Water (e.g. ad libitum): ad libitum, water was withheld for the second urine collection.
- Acclimation period: rats 12-13 d, mice 10 or 14 d

DETAILS OF FOOD AND WATER QUALITY:
Diet: NIH-07 open formula pelleted diet (Zeigler Brothers, Inc., Gardners, PA), available ad libitum except during exposure periods changed weekly
Water: Tap water (City of Chicago municipal supply) via automatic watering system (Edstrom Industries, Waterford, WI), available ad libitum, changed weekly

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23.9°C
- Humidity (%): 55 % +- 15 %
- Air changes (per hr): 15 air changes/hour
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Vehicle:

air

Mass median aerodynamic diameter (MMAD):

>= 1 - <= 1.3 µm

Geometric standard deviation (GSD):

3

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Aerosol leaving the jetmill passed through a one-stage impactor and a vertical elutriator to eliminate or deagglomerate the large particles before entering a plenum and manifold distribution system. The aerosol delivery system consisted of three holding chambers that diluted the aerosol in three stages. A metered amount of diluted aerosol was removed and mixed with conditioned air at the inlet to each exposure chamber to achieve the appropriate exposure concentration. The electrical charge buildup on the aerosol particles was neutralized by mixing the aerosol with high concentrations of bipolar ions, which were generated using a Pulse Gun (Static Control Services, Palm Springs, CA) air nozzle. For the 3-month studies, a transvector air pump was installed at the aerosol inlet to each exposure chamber to provide additional control of the aerosol flow rate and improve stability of the chamber concentration.
- Method of holding animals in test chamber: not specified
- Source and rate of air: not specified
- Method of conditioning air: Chamber Air Supply Filters HEPA (R&R Equipment Sales, Rosemont, IL)
- System of generating particulates/aerosols: For the 16-day and 3-month studies, vanadium pentoxide aerosol generation was based on the principle of pneumatic dispersion and consisted of two major components: a screw feeder (Model 310, Accurate, White Water, WI) that metered vanadium pentoxide powder at a constant rate and a Jet-O-Mizer jetmill (Fluid Energy Corp., Harfield, PA) that used compressed air to disperse the metered powder and form the aerosol.
- Temperature, humidity, pressure in air chamber: 23.9°C, 55 +- 15 % humidity
- Air flow rate: 15 changes/hour
- Air change rate: 15 changes/hour
- Method of particle size determination: The particle size distribution in each chamber was determined prior to the start of all studies, during the first week of the 16-day and 3-month studies, and monthly during the 3-month study. For the 16-day and 3-month studies, a 10-stage Quartz Crystal Microbalance-based cascade impactor (California Measurements, Inc., Sierra Madre, CA) was used to separate the aerosol particles into sequential size ranges; the mass median aerodynamic diameter was calculated from the corresponding mass fraction of particles at each stage.
- Treatment of exhaust air: not specified

TEST ATMOSPHERE
- Brief description of analytical method used: During all studies, chamber aerosol concentrations were monitored with real-time aerosol monitors (RAMs) that used a pulsed-light-emitting diode in combination with a silicon detector to sense light scattered over a forward angular range of 45° to 95° by particles traversing the sensing volume. The instruments respond to particles 0.1 to 20 μm in diameter.
- Samples taken from breathing zone: yes, an individual monitor was used for each exposure chamber

VEHICLE (if applicable)
- Justification for use and choice of vehicle: no details given
- Composition of vehicle: conditioned air
- Concentration of test material in vehicle: 0, 1, 2, 4, 8, or 16 mg/m3
- Purity of vehicle: not specified

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The uniformity of aerosol concentration in the inhalation exposure chambers without animals was evaluated before each of the studies began; concentration uniformity with animals present in the chambers was also measured once during the 3 months studies. RAM measurements were taken from 8 different chamber positions. During the 16-day and 3-month studies, minor excursions in chamber uniformity values (between-port and within-port variability) were observed in one or more exposure chambers, but these excursions had no impact on the studies.

Duration of treatment / exposure:

6 hours plus T90 (15 minutes) per day

Frequency of treatment:

5 days per week for 3 months (core study),
5 days per week for 12 (females) or 13 (males) weeks (Cardiopulmonary physiology study)

Dose / conc.:

0 mg/m³ air

Dose / conc.:

1 mg/m³ air

Dose / conc.:

2 mg/m³ air

Dose / conc.:

4 mg/m³ air

Dose / conc.:

8 mg/m³ air

Dose / conc.:

16 mg/m³ air

No. of animals per sex per dose:

10 male and 10 female rats and mice (core study)
10 male and 10 female rats (Cardiopulmonary physiology study)

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale:
rats: Based on decreased survival and body weight decreases in 32 mg/m3 in the 16 day study, an exposure concentration of 32 mg/m3 was considered too high for use in a 3-month study. Therefore, the exposure concentrations selected for the 3-month inhalation study in rats and mice were 0, 1, 2, 4, 8, and 16 mg/m3.
- Rationale for animal assignment (if not random): Animals were distributed randomly into groups of approximately equal initial mean body weights.

Positive control:

no positive control

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

BODY WEIGHT: Yes
- Time schedule for examinations: animals were weighed initially, weekly, and at the end of the studies

HAEMATOLOGY: Yes
- Time schedule for collection of blood: 4 and 23 and at the end of the study
- Anaesthetic used for blood collection: Yes (70% CO2:30% air mixture)
- Animals fasted: Not specified
- How many animals: 18
- Parameters checked: automated hematocrit; manual hematocrit; hemoglobin concentration; erythrocyte, reticulocyte, nucleated erythrocyte, and platelet counts; erythrocyte morphology; mean cell volume; mean cell hemoglobin; mean cell hemoglobin concentration; leukocyte count and differentials

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood:
4 and 23 and at the end of the study
- Anaesthetic used for blood collection: Yes (70% CO2:30% air mixture)
- Animals fasted: Not specified
- How many animals: 18 rats
- Parameters checked: urea nitrogen, creatinine, total protein, albumin, alanine aminotransferase, alkaline phosphatase, creatine kinase, sorbitol dehydrogenase, bile acids

URINALYSIS: Yes
- Time schedule for collection of urine: during week 12 (females) or 13 (males).
- Metabolism cages used for collection of urine: Yes
- Animals fasted: Yes
- Parameters checked: volume, specific gravity

Sacrifice and pathology:

Sacrifice via CO2 asphyxiation

Necropsy was performed on all core study animals. Organs weighed were the heart, right kidney, liver, lung, right testis, and thymus.

Clinical pathology
Blood was collected from the retroorbital sinus of cardiopulmonary physiology study rats on days 4 and 23 and from core study rats at the end of the studies for hematology and clinical chemistry analyses. Male core study rats exposed to 0, 2, 4, or 8 mg/m3 and female core study rats exposed to 0, 4, 8, or 16 mg/m3 were placed in metabolism cages for urine collection during week 12 (females) or 13 (males).
Hematology: automated hematocrit; manual hematocrit; hemoglobin concentration; erythrocyte, reticulocyte, nucleated erythrocyte, and platelet counts; erythrocyte morphology; mean cell volume; mean cell hemoglobin; mean cell hemoglobin concentration; leukocyte count and differentials
Clinical chemistry: urea nitrogen, creatinine, total protein, albumin, alanine aminotransferase, alkaline phosphatase, creatine kinase, sorbitol dehydrogenase, bile acids
Urinalysis: volume, specific gravity
Urine concentrating ability: volume, specific gravity

Histopathology
Complete histopathology was performed on 0, 8 (rats only), and 16 mg/m3 rats and mice. In addition to gross lesions and tissue masses, the following tissues were examined: adrenal gland, bone with marrow, brain, clitoral gland, esophagus, gallbladder (mice only), heart and aorta, large intestine (cecum, colon, and rectum), small intestine (duodenum, jejunum, and ileum), kidney, larynx, liver, lung and mainstem bronchi, lymph nodes (mandibular, mediastinal, mesenteric, and bronchial), mammary gland, nose, ovary, pancreas, parathyroid gland, pituitary gland, preputial gland, prostate gland, salivary gland, skin, spleen, stomach (forestomach and glandular), testis (with epididymis and seminal vesicle), thymus, thyroid gland, trachea, urinary bladder, and uterus. The lung of rats and mice and nose of rats in all remaining exposure groups and the thymus in 8 mg/m3 mice were also examined.

Other examinations:

Sperm Motility and Vaginal Cytology
At the end of the studies, sperm samples were collected from core study male rats in the 0, 2, 4, and 8 mg/m3 groups and male mice in the 0, 4, 8, and 16 mg/m3 groups for sperm motility evaluations. The following parameters were evaluated: spermatid heads per testis and per gram testis, spermatid counts, and epididymal spermatozoal motility and concentration. The left cauda, left epididymis, and left testis were weighed. Vaginal samples were collected for up to 12 consecutive days prior to the end of the studies from core study female rats and mice exposed to 0, 4, 8, or 16 mg/m3 for vaginal cytology evaluations. The percentage of time spent in the various estrous cycle stages and estrous cycle length were evaluated.

Statistics:

Survival Analyses
The probability of survival was estimated by the product-limit procedure of Kaplan and Meier (1958). Statistical analyses for possible doserelated effects on survival used Cox’s (1972) method for testing two groups for equality and Tarone’s (1975) life table test to identify dose-related trends. All reported P values for the survival analyses are two sided.

Analysis of Continuous Variables
Two approaches were employed to assess the significance of pairwise comparisons between exposed and control groups in the analysis of continuous variables. Organ and body weight data, which historically have approximately normal distributions, were analyzed with the parametric multiple comparison procedures of Dunnett (1955) and Williams (1971, 1972). Hematology, clinical chemistry, urinalysis, urine concentrating ability, cardiopulmonary, immunotoxicologic, cell proliferation, tissue concentrations, spermatid, and epididymal spermatozoal data, which have typically skewed distributions, were analyzed using the nonparametric multiple comparison methods of Shirley (1977) and Dunn (1964).

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

rats: Abnormal breathing, thinness, lethargy, abnormal posture, and ruffled fur were observed in rats exposed to 16 mg/m3. Abnormal breathing, marked by shallow, rapid respiration, was first observed during and immediately following exposure periods; this was observed in all 16 mg/m3 rats by week 2 and in all 8 mg/m3 rats by week 4. By week 9, the abnormal breathing was also observed in 16 mg/m3 rats during nonexposure periods. Some rats in the 16 mg/m3 groups had diarrhea and nasal/eye discharge. Abnormal posture was observed in two males exposed to 8 mg/m3, and one of these rats was thin with ruffled fur and nasal/eye discharge.

Mortality:

mortality observed, treatment-related

Description (incidence):

rats: Seven males and three females exposed to 16 mg/m3 died during the study.
mice: One male exposed to 16 mg/m3 died before the end of the study. The mouse that died early appeared thin. There were no other clinical findings related to vanadium pentoxide exposure.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

rats: Final mean body weights and body weight gains of males exposed to 4 mg/m3 or greater and of females exposed to 16 mg/m3 were significantly less than those of the chamber controls.
mice: Final mean body weights and body weight gains of 8 and 16 mg/m3 males and of 4 mg/m3 or greater females were significantly less than those of the chamber controls.

Food efficiency:

not specified

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

rats: The hematology results indicated that exposure of rats to vanadium pentoxide affected the circulating red cell mass. In general, the erythrocyte counts reflected similar and proportional, but not significant, decreases. There were exposure concentration-related decreases in the mean cell volumes and mean cell hemoglobin values on day 23, which are consistent with a developing erythrocyte microcytosis. The mean cell volumes and/or mean cell hemoglobin values were decreased in 2 mg/m3 or greater males and 4 mg/m3 or greater females, suggesting that the circulating erythrocytes were smaller than expected. At week 13, the erythron decrease had disappeared and was replaced by an erythrocytosis, evidenced by substantial increases in hematocrit values, hemoglobin concentrations, and erythrocyte counts in 16 mg/m3 males and females. The erythrocytosis was accompanied by increased reticulocyte and/or nucleated erythrocyte counts, suggesting that an increased production of erythrocytes contributed to the erythrocytosis.

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

rats: Serum alanine aminotransferase activities were increased. Stress-related corticosteroid-induced increases in liver alanine aminotransferase activities may, in part, help explain this . At all time points, there were generally exposure concentration-related decreases in serum alkaline phosphatase activities and total protein and albumin concentrations in males and females. At week 13, urea nitrogen concentrations were increased in 16 mg/m3 males and females, suggesting a possible effect on renal clearance. However, creatinine concentrations, another marker of renal clearance, were minimally decreased on day 23 in 8 mg/m3 males and at week 13 in 16 mg/m3 males and females; these decreases would be consistent with the decreased body weights observed in these groups. Since alkaline phosphatase activity and total protein, albumin, and urea nitrogen concentrations can be affected by altered nutritional status, the changes in these variables may have been related secondarily to body weight decreases and altered food intake. Significant increases and decreases in bile acid concentrations and creatine kinase activities in various exposure groups at various time points were not considered to be toxicologically relevant.

Urinalysis findings:

effects observed, non-treatment-related

Description (incidence and severity):

rats: After 12 (females) or 13 (males) weeks of exposure, the baseline (water-replete) overnight urine collection demonstrated decreased urine volumes and increased urine specific gravities in the 8 mg/m3 male and 16 mg/m3 female groups, suggesting these animals were able to concentrate their urine; the 16 mg/m3 male group was not tested. These findings also suggest that these exposure groups may have been in a partially dehydrated state prior to the water deprivation studies. For baseline and water deprivation test samples, microscopic evaluation of the urine demonstrated slight increases in formed elements in 8 mg/m3 males (baseline: casts, epithelial cells, erythrocytes, and leukocytes; water-deprived: casts) and 16 mg/m3 females (baseline and water deprived: leukocytes) (data not presented). While changes in formed urine elements can be indicative of various renal effects, the alterations in this study were not excessive and possibly reflected the hydration status of the animals; they were not considered to be toxicologically relevant.

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

rats: Absolute and relative lung weights of 4 mg/m3 or greater males and females were significantly greater than those of the chamber controls; in addition, the relative lung weights of 2 mg/m3 males were significantly greater than those of the chamber controls.
mice: Absolute and relative lung weights of males and females exposed to 4 mg/m3 or greater were significantly greater than those of the chamber controls. The absolute lung weight was also significantly increased in males exposed to 2 mg/m3.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

rats: The carcasses of males and females exposed to 16 mg/m3 were very thin, and the spleens and thymuses appeared disproportionately small. Lungs of 4 mg/m3 or greater males and 8 and 16 mg/m3 females varied from red to pale or mottled.
mice: Gross findings were observed in males and females exposed to 8 or 16 mg/m3 and included lungs that were pale or contained white or red (females) foci; the lungs of males in these groups were sometimes gray or mottled.

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

rats: There were significant increases in the incidences of epithelial hyperplasia of the lung in males and females exposed to 2 mg/m3 or greater. The incidences of inflammation or fibrosis were significantly increased in males exposed to 2 mg/m3 or greater and females exposed to 4 mg/m3 or greater. The incidences of hyperplasia and metaplasia of the nasal respiratory epithelium were significantly increased in males exposed to 8 or 16 mg/m3 and in females exposed to 4 mg/m3 or greater. There were significantly increased incidences of inflammation of the nose in males and females exposed to 16 mg/m3.
mice: The incidences of inflammation of the lung were increased in mice exposed to 2 mg/m3 or greater. Mice exposed to 2 mg/m3 or greater had epithelial hyperplasia of the lung. The severities of these lesions generally increased with increasing exposure concentration. Inflammation was characterized by multiple foci of a mixed cellular infiltrate oriented around blood vessels and bronchioles. The infiltrate was composed primarily of macrophages with abundant cytoplasm and fewer lymphocytes and neutrophils. The infiltrate extended into the surrounding perivascular interstitium and often filled adjacent alveoli. Hyperplasia involved alveolar and, to a lesser extent, bronchiolar epithelium. This change involved the distal airways and associated alveolar ducts and alveoli. Normally flattened epithelium was replaced with larger cuboidal cells.

Other effects:

effects observed, treatment-related

Description (incidence and severity):

rats: Vanadium pentoxide exposure did not affect reproductive endpoints in males, but it did increase estrous cycle length in females exposed to 8 mg/m3 and reduced the number of cycling females in the 16 mg/m3 group.
mice: The epididymal spermatozoal motility of males exposed to 8 or 16 mg/m3 was significantly decreased. No significant differences were noted in estrous cycle parameters between exposed and chamber control females.

Dose descriptor:

NOAEL

Remarks:

rats and mice

Effect level:

1 mg/m³ air

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: pulmonary effect

Critical effects observed:

yes

Lowest effective dose / conc.:

2 mg/m³ air

System:

respiratory system: lower respiratory tract

Organ:

alveoli

bronchi

bronchioles

lungs

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Critical effects observed:

yes

Lowest effective dose / conc.:

4 mg/m³ air

System:

respiratory system: upper respiratory tract

Organ:

other: nose (respiratory epithelium covering the ventral portion of the nasal septum, the vomeronasal organ, and, to a lesser extent, the ventral lateral walls of the anterior portion of the nasal cavity)

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Cardiopulmonary Physiology Studies

Decreases in heart rate and in diastolic, systolic, and mean blood pressure were observed in male and female rats exposed to 16 mg/m3. It is unlikely that this response was the result of a direct cardiotoxic action of vanadium pentoxide, rather, it was considered to be a reflection of the poor condition of the animals coupled with an effect from anesthesia.

Significant exposure-related changes in pulmonary function were observed in male and female rats exposed to 4, 8, or 16 mg/m3. Only slight differences were observed between males and females, and the differences were not considered to be biologically significant. These results indicate that a more restrictive lesion was present in groups exposed to 4 mg/m3 or greater, evidenced by reduced lung compliance, changes in breathing measurements, impaired capacity to diffuse carbon monoxide, reduced static and dynamic lung volumes, and exaggerated flows. Exposure concentration-related decreases in chord, peak, and dynamic compliance were consistent with reduced lung elasticity. There was also an increase in respiratory rate and a decrease in tidal volume; these alterations are known to increase breathing efficiency in response to a restrictive disease. This breathing pattern preferentially ventilates airway dead space and results in increased minute volume to maintain adequate blood gas. Also characteristic of restrictive disease were reduced carbon monoxide diffusing capacity, which signifies obstructed airways and changes in membrane composition (thickened interstitium). The decrease in static lung volume (total lung capacity and vital capacity) and exaggerated flows, as described by flow volume curves corrected for lung volume, also were suggestive of restrictive disease.

Pulmonary function changes indicate an obstructive disease in the 16 mg/m3 groups, evidenced by changes in breathing mechanics, static lung volumes, and forced expiratory maneuvers. Expiratory resistance, an indicator of bronchoconstriction, and end expiratory and residual volume were increased, while dynamic lung volume was decreased. These changes suggest closure of distal airways due to extensive pathology, resulting in air being trapped in the alveoli and reduced flow during forced expiratory maneuvers. Lung pathology in rats exposed to 16 mg/m3 was not drastically different than that observed in rats exposed to 8 mg/m3. Thus, it is not clear whether pulmonary function results indicate an obstructive disease or merely reflect the deteriorating condition of the 16 mg/m3 rats.

Together, the pulmonary function changes indicate that a restrictive disease was present in male and female rats exposed to 4 mg/m3 or greater, while an obstructive lung disease may have been present only in the 16 mg/m3 groups.

The pulmonary lavage data indicate an inflammatory response in the lungs of exposed rats. In general, there were no differences between males and females. Exposure concentration-related increases were observed in the total numbers of cells, lymphocytes, neutrophils, and protein recovered in pulmonary lavage fluid from rats exposed to vanadium pentoxide at concentrations up to 8 mg/m3. The percentages of macrophages in lavage fluid were similar between exposed and chamber control rats. However, in female rats exposed to 8 mg/m3 there was a decrease in the numbers of macrophages with concomitant increases in the numbers of neutrophils and lymphocytes. These endpoints also were affected in the 16 mg/m3 group, but to a lesser extent, which is most likely due to the overt toxicity of vanadium pentoxide evidenced by decreased body weights and severe bronchoconstriction and airway obstruction.

Conclusions:

the 16 mg/m3 concentration was lethal to several rats and one male mouse; body weights were severely reduced in rats exposed to 16 mg/m3. The respiratory tract was clearly the primary site of toxicity in rats and mice exposed to vanadium pentoxide, with rats being somewhat more severely affected than mice. The respiratory effects were more intense with increased exposure time, as indicated by increased lung weights and a greater spectrum and increased severity of proliferative and inflammatory lesions in the lungs of most exposed rats and mice in the 3-month studies. Alveolar/bronchiolar epithelial hyperplasia was present in all mice exposed to 8 or 16 mg/m3, but occurred with greater severity and was present in all rats exposed to 2 mg/m3 or greater. The severities of pulmonary inflammation were similar between rats and mice, but the incidences of this lesion were significantly increased at lower concentrations in rats. Minimal to moderate fibrosis of the lung occurred in rats exposed to 2 mg/m3 or greater. The no-observed-adverse-effect level for lungs was 1 mg/m3 in rats and was not determined in mice. Taken together, hyperplastic and inflammatory lesions, the presence of exudate in the bronchioles, and lavage fluid analysis supported conclusions from the pulmonary function tests that indicated restrictive lung disease in rats exposed to 4 mg/m3 or greater.

A NOAEL of 1 mg/m3 can be derived for rats and mice from these two 13-week studies with vanadium pentoxide.

Executive summary:

Rats

Groups of 10 male and 10 female rats were exposed to particulate aerosols of vanadium pentoxide at concentrations of 0, 1, 2, 4, 8, or 16 mg/m3 by inhalation, 6 hours per day, 5 days per week for 3 months. Seven males and three females exposed to 16 mg/m3 died during the study. Mean body weights were significantly less in males exposed to 4 mg/m3 or greater and in females exposed to 16 mg/m3. Abnormal breathing, thinness, lethargy, abnormal posture, and ruffled fur were observed in rats exposed to 16 mg/m3.

Hematology results indicated that exposure of rats to vanadium pentoxide induced a microcytic erythrocytosis in males and females. Absolute and relative lung weights were significantly greater for 4 mg/m3 or greater males and females than for the chamber controls as were the relative lung weights of 2 mg/m3 males. The estrous cycle of females exposed to 8 mg/m3 was significantly longer than that of the chamber control group, and the number of cycling females in the 16 mg/m3 group was reduced. The incidences of several nonneoplastic lesions of the lung and nose were significantly increased in males and females exposed to 2 mg/m3 or greater. Data from pulmonary function analyses indicated that a restrictive lung disease was present in male and female rats exposed to 4 mg/m3 or greater, while an obstructive lung disease was present only in the 16 mg/m3 groups.

Mice

Groups of 10 male and 10 female mice were exposed to particulate aerosols of vanadium pentoxide at concentrations of 0, 1, 2, 4, 8, or 16 mg/m3 by inhalation, 6 hours per day, 5 days per week for 3 months. One male exposed to 16 mg/m3 died before the end of the study. Mean body weights of 8 and 16 mg/m3 males and 4 mg/m3 or greater females were significantly less than those of the chamber controls. Absolute and relative lung weights of males and females exposed to 4 mg/m3 or greater were significantly greater than those of the chamber controls. The epididymal spermatozoal motility of males exposed to 8 or 16 mg/m3 was significantly decreased. Some mice exposed to 2 or 4 mg/m3 had inflammation of the lung, and all mice exposed to 8 or 16 mg/m3 had inflammation and epithelial hyperplasia of the lung.

A NOAEL of 1 mg/m3 can be derived for rats and mice from these two 13-week studies with vanadium pentoxide.

Cross-reference 4

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

toxicity to reproduction: other studies

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Justification for type of information:

please refer to Read-across statement attached in section 13

Reason / purpose for cross-reference:

read-across source

Dose descriptor:

LOAEL

Remarks:

mice

Effect level:

30.6 mg/m³ air

Based on:

test mat.

Remarks:

converted to VAA (for details on the calculation please refer to 'overall remarks'

Sex:

male

Basis for effect level:

other: epididymal sperm motility

Remarks on result:

other: The epididymal spermatozoal motility of males exposed to 8 or 16 mg/m3 was significantly decreased

The epididymal spermatozoal motility of male mice exposed to 8 or 16 mg/m3 was significantly decreased (Table 3). No significant differences were noted in estrous cycle parameters between exposed and chamber control female mice (Table 4). In rats no significant changes were observend in sperm motility. The estrous cycle length was significant longer than the chamber control in the 8 mg/m3 doese group, but not in the 16 mg/m3 dose group. (table 1 and 2).

Table 1 Summary of Reproductive Tissue Evaluations for Male Rats in the 3-Month Inhalation Study of Vanadium Pentoxide^a
	Chamber control	2 mg/m^3	4 mg/m^3	8 mg/m^3
n	10	10	10	10
Weights (g)
Necropsy body wt	350±8	339 ± 6	334 ± 7	319±7**
L. Cauda epididymis	0.1742±0.0062	0.1666±0.0042	0.1809±0.0043	0.1768±0.0056
L. Epididymis	0.4967±0.0076	0.4756 ± 0.0081	0.4896 ± 0.0097	0.5075 ± 0.0050
L. Testis	1.4960±0.0292	1.4606 ± 0.0326	1.5077 ± 0.0265	1.4908 ± 0.0183
Spermatid measurements
Spermatid heads (10^7/g testis)	9.70 ± 0.44	9.89 ± 0.58	9.35±0.39	8.91±0.42
Spermatid heads (10^7/testis)	14.42 ± 0.49	14.34 ± 0.72	14.08±0.59	13.30±0.69
Spermatid count (mean/10^-4mL suspension)	72.10±2.45	71.70±3.59	70.40 ± 2.94	66.50±3.45
Epididymalspermatozoal measurements
Motility(%)	85.68 ± 1.77	85.51 ± 2.21	87.69 ± 1.47	80.14±2.45
Concentration (10^6/g caudaepididymaltissue)	427 ± 15	463 ± 11	436±28	386±24
** Significantly different (P≤0.01) from the chamber control group by Williams' test ^aData are presented as mean ± standard error. Differences from the chamber control group are not significant by Dunnett's test (tissue weights) or Dunn's test (spermatid and epididymal spermatozoal measurements).

Table 2 Estrous Cycle Characterization for Female Rats in the 3-Month Inhalation Study of Vanadium Pentoxide^a
	Chamber Control	4 mg/m^3	8 mg/m^3	16 mg/m^3
n	10	10	10	8
Necropsy body wt	198 ± 3	196 ± 4	189 ± 4	117±5**
Estrous cycle length (days)	5.00 ± 0.00	5.00 ± 0.08	5.50±0.14**b	5.25± 0.25^c
Estrous stages (% of cycle)
Diestrus	39.2	40.8	49.2	71.9
Proestrus	18.3	16.7	15.8	10.4
Estrus	20.8	19.2	17.5	10.4
Metestrus	21.7	22.5	17.5	7.3
Uncertain diagnoses	0.0	0.8	0.0	0.0
** Significantly different (P≤0.01) from the chamber control group by Williams' test (necropsy body weight) or Shirley's test (estrous cycle length) ^aNecropsy body weight and estrous cycle length data are presented as mean ± standard error. By multivariate analysis of variance, exposed females do not differ significantly from the chamber control females in the relative length of time spent in the estrous stages. ^bEstrous cycle was longer than 12 days or was unclear in 1 of 10 animals. ^cEstrous cycle was longer than 12 days or was unclear in six of eight animals.

Table 3 Summary of Reproductive Tissue Evaluations for Male Mice in the 3-Month Inhalation Study of Vanadium Pentoxide^a
	Chamber Control	4 mg/m^3	8mg/m^3	16mg/m^3
n	10	10	10	9
Weights (g)
Necropsy body wt	35.4±1.1	34.5 ± 0.5	33.4±0.4	32.0±0.6**
L. Cauda epididymis	0.0170±0.0010	0.0174 ± 0.0006	0.0180±0.0006	0.0165±0.0009
L. Epididymis	0.0525±0.0012	0.0505 ± 0.0013	0.0546 ± 0.0013	0.0512±0.0013
L. Testis	0.1209±0.0025	0.1217±0.0014	0.1166±0.0020	0.1163±0.0018
Spermatid measurements
Spermatid heads (10^7/g testis)	17.97±0.67	15.99 ± 0.71	17.93±0.74	17.67±0.74
Spermatid heads (10^7/testis)	2.17±0.09	1.94 ± 0.08	2.09 ± 0.09	2.05 ± 0.08
Spermatid count (mean/10^-4mL suspension)	67.83±2.68	60.68 ±2.50	62.28 ± 2.89	64.06 ± 2.47
Epididymalspermatozoal measurements
Motility(%)	88.63± 0.90^b	86.23 ± 1.64	77.10± 3.15**^b	83.11± 2.48*^c
Concentration (10^6/g caudaepididymaltissue)	894 ± 57	915 ± 55	818 ± 39	849 ± 98
* Significantly different (P≤0.05) from the chamber control group by Shirley's test ** Significantly different (P≤0.01) from the chamber control group by Williams' test (necropsy body weight) or Shirley's test (epididymal spermatozoal motility) ^aData are presented as mean ± standard error. Differences from the chamber control group are not significant by Dunnett's test (tissueweights) or Dunn's test (spermatid measurements and epididymal spermatozoal concentration). ^bn=9 ^cn=8

Table 4 Estrous Cycle Characterization for Female Mice in the 3-Month Inhalation Study of Vanadium Pentoxide^a
	Chamber Control	4 mg/m^3	8 mg/m^3	16 mg/m^3
n	10	10	10	10
Necropsy body wt	31.1±1.0	26.2±0.4**	27.3 ± 0.4**	25.8 ± 0.4**
Estrous cycle length (days)	4.25 ± 0.13	4.29±0.15	4.05 ± 0.05	5.11± 0.51^c
Estrous stages (% of cycle)
Diestrus	27.5	40.8	29.2	34.2
Proestrus	21.7	14.2	15.0	18.3
Estrus	29.2	26.7	33.3	30.8
Metestrus	21.7	18.3	22.5	15.8
Uncertain diagnoses	0.0	0.0	0.0	0.8
** Significantly different (P≤0.01) from the chamber control group by Williams' test ^aNecropsy body weight and estrous cycle length data are presented as mean ± standard error. Differences from the chamber control group forestrous cycle length are not significant by Dunn's test. By multivariate analysis of variance, exposed females do not differ significantlyfrom the chamber control females in the relative length of time spent in the estrous stages. ^bEstrous cycle was longer than 12 days or was unclear in 3 of 10 animals. ^cEstrous cycle was longer than 12 days or was unclear in 1 of 10 animals.

Conclusions:

The epididymal spermatozoal motility of male mice exposed to 8 or 16 mg/m3 was significantly decreased. No significant differences were noted in estrous cycle parameters between exposed and chamber control female mice. In male rats no significant changes were observend in sperm motility. The estrous cycle length in female rats was significant longer than the chamber control in the 8 mg/m3 dose group, but not in the 16 mg/m3 dose group. 8 mg/m3 corresponds to a dose of 30.6 mg/m3 when converted to the target substance vanadium acetylacetonate.

Executive summary:

Groups of 10 male and 10 female rats were exposed to particulate aerosols of vanadium pentoxide at concentrations of 0, 1, 2, 4, 8, or 16 mg/m3 by inhalation, 6 hours per day, 5 days per week for 3 months. Reproductive tissues were examined and estrous cycle and sperm measurements were performed. The following effects were observed: The epididymal spermatozoal motility of male mice exposed to 8 or 16 mg/m3 was significantly decreased. No significant differences were noted in estrous cycle parameters between exposed and chamber control female mice. In male rats no significant changes were observend in sperm motility. The estrous cycle length in female rats was significant longer than the chamber control in the 8 mg/m3 dose group, but not in the 16 mg/m3 dose group. 8 mg/m3 corresponds to a dose of 30.6 mg/m3 when converted to the target substance vanadium acetylacetonate.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2002

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

not specified

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Divanadium pentaoxide

EC Number:

215-239-8

EC Name:

Divanadium pentaoxide

Cas Number:

1314-62-1

Molecular formula:

O5V2

IUPAC Name:

dioxovanadiooxy(dioxo)vanadium

Specific details on test material used for the study:

no details given

Method

Target gene:

L-histidine loci

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 97

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 98

Species / strain 3

Species / strain / cell type:

S. typhimurium TA 100

Species / strain 4

Species / strain / cell type:

S. typhimurium TA 1535

Species / strain 5

Species / strain / cell type:

S. typhimurium TA 102

Metabolic activation:

with and without

Metabolic activation system:

S9 mix (metabolic activation enzymes and cofactors from Aroclor 1254-induced male Sprague-Dawley rat or Syrian hamster liver)

Test concentrations with justification for top dose:

0.00, 0.03, 0.10, 0.30, 1.00, 3.00, 6.00, 10.00, 33.00 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: no data

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

sodium azide

mitomycin C

other: 4-nitro-o-phenylenediamine / 2-aminoanthracene

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation
- Cell density at seeding (if applicable):

DURATION
- Preincubation period: 20 min
- Exposure duration: 2 days
- Selection time (if incubation with a selection agent): 2 days

SELECTION AGENT (mutation assays): L-histidine

NUMBER OF REPLICATIONS: triplicate plates

Rationale for test conditions:

not specified

Evaluation criteria:

In this assay, a positive response is defined as a reproducible, dose-related increase in histidine-independent (revertant) colonies in any one strain/activation combination. An equivocal response is defined as an increase in revertants that is not dose related, is not reproducible, or is not of sufficient magnitude to support a determination of mutagenicity. A negative response is obtained when no increase in revertant colonies is observed following chemical treatment. There is no minimum percentage or fold increase required for a chemical to be judged positive or weakly positive.

Statistics:

not specified

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 97

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

slight toxicity at highest concentration tested

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 5

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

Vanadium pentoxide (0.03 to 333.00 μg/plate) was not mutagenic in Salmonella typhimurium strain TA97, TA98, TA100, TA102, or TA1535 with or without induced rat or hamster liver S9 enzymes.

Applicant's summary and conclusion

Conclusions:

Vanadium pentoxide (0.03 to 333.00 μg/plate) was not mutagenic in Salmonella typhimurium strain TA97, TA98, TA100, TA102, or TA1535 with or without induced rat or hamster liver S9 enzymes.

Executive summary:

Vanadium pentoxide was tested similar to OECG Guideline 471 (preincubation method) in S. typhimurium strain TA97, TA98, TA100, TA102, or TA1535 with or without induced rat or hamster liver S9 enzymes at 8 concentrations ranging between 0.03 and 333 µg/plate. As a result, all tests were negative.