Vanadyl pyrophosphate

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study conducted using methods similar to accepted test guidelines and published in a peer reviewed journal

Data source

Reference

Reference Type:

publication

Title:

Developmental toxicity of vanadium in mice after oral administration

Author:

Paternain JL, Domingo JL, Gomez M, Ortega A and Corbella J

Year:

1990

Bibliographic source:

Journal of Applied Toxicology 10(3): 181-186, 1990

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

yes

Remarks:

Mouse rather than rat used

GLP compliance:

not specified

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

vanadyl sulphate pentahydrate

IUPAC Name:

vanadyl sulphate pentahydrate

Constituent 2

Reference substance name:

14708-82-8

Cas Number:

14708-82-8

IUPAC Name:

14708-82-8

Details on test material:

- Name of test material (as cited in study report): Vanadyl sulphate pentahydrate
- Molecular formula (if other than submission substance): VOSO4.5H2O
- Molecular weight (if other than submission substance): 253.077
- Smiles notation (if other than submission substance): [V+2]=O.O.O.O.O.O.S(=O)(=O)([O-])[O-]
- InChl (if other than submission substance): 1/H2O4S.5H2O.O.V/c1-5(2,3)4;;;;;;;/h(H2,1,2,3,4);5*1H2;;/q;;;;;;;+2/p- 2/rH2O4S.OV.5H2O/c1-5(2,3)4;1-2;;;;;/h(H2,1,2,3,4);;5*1H2/q;+2;;;;;/p-2
- Structural formula attached as image file (if other than submission substance): see Fig. 3

Test animals

Species:

mouse

Strain:

Swiss

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Panlab, Barcelona, Spain
- Age at study initiation: No data
- Weight at study initiation: 25 - 30 g
- Fasting period before study: No
- Housing: Mating phase - 1 male/2 females per cage, otherwise not detailed
- Diet (e.g. ad libitum): Panlab commercial rodent diet, ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 10 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 - 23 deg C
- Humidity (%): 40 - 50 % RH
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

- Impregnation procedure: cohoused
- M/F ratio per cage: 1 male / 2 females
- Length of cohabitation: No data
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy
- Any other deviations from standard protocol: None reported

Duration of treatment / exposure:

Days 6-15 of gestation

Frequency of treatment:

Daily

Duration of test:

18 days

Doses / concentrations

Remarks:

Doses / Concentrations:
37.5, 75 or 150 mg/kg/day
Basis:
nominal conc.

No. of animals per sex per dose:

22 mated, sperm positive, females / dose group

Control animals:

yes, concurrent vehicle

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Daily
- Cage side observations included mortaility / morbidity.

DETAILED CLINICAL OBSERVATIONS: No data

BODY WEIGHT: Yes
- Time schedule for examinations: Daily throughout gestation (during pre-treatment, treatment and post-treatment periods)

FOOD CONSUMPTION AND COMPOUND INTAKE: Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/animal/3 or 6 day period

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 18
- Organs examined: Liver, kidney, gravid uterus and placentae weighed

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes

Fetal examinations:

- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: 1/3 per litter
- Skeletal examinations: Yes: 2/3 per litter
- Head examinations: No data

Statistics:

Continuous data (maternal body weight, body weight gain, food consumption, etc.) were analysed using a one-way analysis of variance with significant F values analysed further using Student's f-test or the Mann-Whitney U test. Statistical comparison of the vanadium analyses were by Student's t-test (one tailed) with a Bonferroni correction for multiple comparisons between treatment groups. A probability of P < 0.05 was used as the criterion of statistical significance. Incidence data were compared using X2 contingency tables with each test group compared to the control group when X2 was significant.

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
Mean maternal body weight gain during the pretreatment interval (Days 0-6 of gestation) was comparable between treated and control groups. There were significant decreases in body weight gain during the exposure period (Days 6-15 of gestation) in treated animals. This was dose-related and observed at all dose levels. Body weight gain during the post-exposure period (Days 15-18 of gestation) indicated that treated animals gained less weight than controls although these differences were not statistically significant.
There was no significant differences between groups in food consumption although an apparent decrease in the mean food consumption was observed for the 75 and 150 mg/kg/day treatment groups from Day 0 to Day 18 of gestation.
A treatment-related affect on maternal organ weights, including absolute and corrected body weight, absolute liver weight, absolute kidney weight and placenta weight was apparent on termination. Gravid uterine weights were significantly lower at all dose levels compared with controls. Absolute maternal liver weight (but not relative liver weight) was significantly decreased at the two higher dose levels, 75 and 150 mg/kg/day, and absolute kidney weight was significantly decreased at 150 mg/kg/day.

Effect levels (maternal animals)

1

Dose descriptor:

NOAEL

Effect level:

37.5 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Remarks on result:

not determinable

Remarks:

no NOAEL identified

2

Dose descriptor:

NOAEL

Effect level:

37.5 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Remarks on result:

not determinable

Remarks:

no NOAEL identified

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:yes

Details on embryotoxic / teratogenic effects:
Treatment had no effect on the number of total implantations, live and dead foetuses, late resorptions per litter, or on the percentage of post-implantation losses or the sex ratio. The incidence of early resorptions per litter exhibited a dose-related increase in all treatment groups.
Mean foetal body weights and the mean foetal body lengths were significantly lower in the treated groups compared to controls and there was a significant incidence of stunted fetuses in the 75 and 150 mg/kg/day groups relative to controls.

Selected foetal tissues were analysed for vanadium. Vanadium could not be detected in the tissues of control animals. It was present at detectable levels in both maternal and foetal tissues of treated animals.

Cleft palate and micrognathia were the most significant external malformations observed in the 150 mg/kg/day group. The total number of external defects was statistically significant for all treated groups relative to controls. The only incidental abnormality observed after visceral examination was hydrocephaly in fetuses from dams receiving 75 or 150 mg/kg/day.

Increased incidence of skeletal variations was seen in all treated groups. Decreased ossification of the supraoccipital bone and decreased ossification of the carpus and tarsus were the most common findings. The increase in the total number of skeletal defects was significantly different from the controls in all the treated groups, this increase being dose-dependent.

Effect levels (fetuses)

1

Dose descriptor:

NOAEL

Effect level:

37.5 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: embryotoxicity

Remarks on result:

not determinable

Remarks:

no NOAEL identified

2

Dose descriptor:

NOAEL

Effect level:

37.5 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: fetotoxicity

Remarks on result:

not determinable

Remarks:

no NOAEL identified

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Any other information on results incl. tables

Maternal toxicity

Observation		Dose level(mg/kg/day)
		0	37.5	75	150
Number of dams		20	16	20	20
Weight gain (g)	Day 6-15 (treatment period)	18.41	10.01*	8.58**	7.63**
	Day 0-18 (total study period)	29.75	24.30*	20.07*	18.48**
Food consumption (g/dam)	Day 6-15 (treatment period)	46.00	37.87	38.90	40.50
	Day 0-18 (total study period)	89.92	89.31	84.20	85.30
Terminal weight (g)		54.62	44.31*	45.49**	43.47**
Organ weights (g)	Liver	2.53	2.11	2.02 *	1.98 *
	Kidney	0.41	0.40	0.35 *	0.34 *
	Gravid uterus	20.61	14.24*	16.50*	15.03*
	Placenta	0.15	0.15	0.15	0.14**

Significantly different to controls; * p<0.05); **p<0.01

Litter parameters

	Dose level(mg/kg/day)
	0	37.5	75	150
No. litters	20	16	20	20
No. implantations/litter	12.6	11.2	12.3	12.8
No. early resorptions/litter	0.30	1.7*	0.70*	1.2*
No. late resorptions/litter	0.00	0.00	0.10	0.22
No. dead foetuses/litter	0.10	0.00	0.50	0.20
No. live foetuses/litter	12.2	9.5	11.0	11.2
Post-implantation loss (%)	3.1	15.1	10.5	12.5
Sex ratio (M/F)	1.03	0.85	0.83	0.89
Foetal body weight (g)	1.35	1.18 **	1.18 **	1.07 **
Foetal body length (mm)	28.7	27.7 *	24.4 **	23.4 **

Significantly different to controls; * p<0.05); **p<0.001

Foetal abnormalities

	Dose level(mg/kg/day)
	0	37.5	75	150
External abnormalities
No. examined/No. litters	240/20	152/16	220/20	188/20
No. stunted foetuses/affected litters	2/2	15/2	11/7*	31/12***
Haematoma   -  face	0	4 (3)**	2 (1)	5 (4)**
-  neck	2/2	9/4 **	3/2	12/8 **
-  thorax	0	0	2/2	6/4 **
-  limbs	0	0	4/2	0
-  dorsal	0	8/2 *	5/2 *	4/2 *
Anophthalmia / microphthalmia	0	10/3	0	0
Exencephaly	2/1	0	0	4/3
Exophthalmia	0	0	4/3	0
Cleft palate	0	0	4/3	58/12 ***
Micrognathia	0	2 (1)	3 (1)	12/3 ***
Club foot	0	0	0	4/2
Curled tail	0	0	2/1	2/2
Total external defects	4/2	22/8 ***	25/11 ***	76/17 ***
Visceral abnormalities
Hydrocephaly	0	0	2/2	4/3
Skeletal abnormalities
No. examined/No. litters	120/20	70/16	117/20	86/20
Reduced ossification -   Supraoccipital	6/3	4/3	28/7*	38/13 ***
-   Carpus	0	10/2 ***	7/3 ***	16/6 ***
-   Tarsus	0	10/2 ***	12 (2)***	27/8 ***
-   Sternebrae	4/2	8/2 *	8/3	10/3 *
Bipartite sternebrae	7/3	3/2	18/9 **	23/12 ***
Asymmetric ribs	9/4	13/9 *	44/15 ***	69/20 ***
Total skeletal defects	9/4	13/9 *	44/15 ***	69/20 ***

Significantly different to controls; *p<0.05); **p<0.01; ***p<0.001

Tissue vanadium concentration(µg/g wet weight)

Organ	Dose level(mg/kg/day)
	0	37.5	75	150
Dam liver	<loq	0.484	0.850	1.589
Dam kidney	<loq	0.493	0.769	1.912
Dam spleen	<loq	0.707	1.340	2.369
Placenta	<loq	0.226	0.375	0.640
Foetus	<loq	1.588	2.896	4.492

Loq: Limit of quantitation

Applicant's summary and conclusion

Conclusions:

Maternal toxicity was apparent as decreased weight gain and reduced body weight in pregnant mice treated with vanadyl sulphate pentahydrate at doses of 37.5, 75 or 150 mg/kg/day. Effects on foetal weights and lengths, in addition to an increased incidence of poorly ossified skeletal elements at all dose levels was seen as embryofoetotoxicity. Treatment resulted in increased incidence of external malformations and gross, visceral and skeletal variations with cleft palate and micrognathia being the major gross malformations seen at the highest dose level (150 mg/kg/day).
The No Observed Effect Level (NOEL) for maternal toxicity, embryotoxicity, foetotoxicity and teratogenicity was less than 37.5 mg/kg/day.

Executive summary:

A prenatal developmental toxicity study has been undertaken on vanadyl sulphate pentahydrate using methods similar to those described in OECD TG No. 414.

Maternal toxicity was apparent as decreased weight gain and reduced body weight in pregnant mice treated with vanadyl sulphate pentahydrate at doses of 37.5, 75 or 150 mg/kg/day. Effects on foetal weights and lengths, in addition to an increased incidence of poorly ossified skeletal elements at all dose levels was seen as embryofoetotoxicity. Treatment resulted in increased incidence of external malformations and gross, visceral and skeletal variations with cleft palate and micrognathia being the major gross malformations seen at the highest dose level (150 mg/kg/day).

The No Observed Effect Level (NOEL) for maternal toxicity, embryotoxicity, foetotoxicity and teratogenicity was less than 37.5 mg/kg/day.