Nickel sulphate

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

experimental study

Adequacy of study:

key study

Study period:

not reported

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline Study

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Principles of method if other than guideline:

According to OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

GLP compliance:

yes

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

Nickel sulphate

EC Number:

232-104-9

EC Name:

Nickel sulphate

Cas Number:

7786-81-4

Molecular formula:

NiSO4

IUPAC Name:

nickel(2+) sulfate

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Raleigh, NC, USA.
- Age at study initiation: 8 weeks
- Weight at study initiation: 239-267 g
- Assigned to test groups randomly: [no/yes, under following basis: ]
- Fasting period before study: not reported
- Housing: 2 per cage
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 64 - 79 deg F
- Humidity (%): humidity 30-70%
- Air changes (per hr): 10 per hr
- Photoperiod (hrs dark / hrs light): 12 hr light/dark cycle.

IN-LIFE DATES: From: April 21, 2003 To: Aug. 2003

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

- Vehicle(s)/solvent(s) used: Cell culture control water
- Lot No: 017156 and 01100526

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: each day the test article was prepared by adding to the vehicle. Formulations held at room temperature.
Animals were dosed by oral gavage once daily for three consecutive days to six males per dose level. The dose levels were 125, 250, or 500 mg/kg/day.

DIET PREPARATION
- not applicable

Duration of treatment / exposure:

3 days

Frequency of treatment:

Once daily

Post exposure period:

24 hours after 3rd dose

Doses / concentrations

Remarks:

Doses / Concentrations:
125, 250, 500 mg/kg-d
Basis:
nominal conc.

No. of animals per sex per dose:

6 per dose

Control animals:

yes, concurrent vehicle

Positive control(s):

Cyclophosphamide was used as the positive control administered by oral gavage dissolved in deionized water at a dose of 60 mg/kg

Examinations

Tissues and cell types examined:

Animals were euthanized approximately 24 hours after the third dose for extraction of bone marrow.
Blood was also collected prior to euthanization.
Nickel in bone marrow and blood was analyzed by AAS.

Details of tissue and slide preparation:

Following centrifugation to pellet the marrow, the supernatant was spread on slided fixed with methanol and stained in acridine orange, dried, and analyzed under fluorescent microscopy.

Evaluation criteria:

Slides were scored for micronuclei and to determine the PCE to NCE cell ratio. The percent micronucleated cells was determine by analyzing micronuclei from at least 2000 PCEs per animal. The criteria were those of Schmid 1976.

Statistics:

Data analysis was conducted using ANOVA

Results and discussion

Test results

Sex:

male

Genotoxicity:

negative

Toxicity:

no effects

Remarks:

no cytotoxicity effects on bone marrow even at maximum tolerated dose established based on mortality and clinical observations

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

RESULTS OF RANGE-FINDING STUDY
- Dose range: 125-1750 mg/kg-day
- No cytotoxicity observed at 750 or 1000 mg/kg-day. Mean PCE:NCE ratios were 0.32 and 0.64 compared to 0.81 (control)
- Other: the maximum tolerated dose was estimated at 500 mg/kg-day

RESULTS OF DEFINITIVE STUDY
Clinical signs of toxicity were noted in all treatment animals including hypoactivity, salivation, black feces, irregular respiration, squinted/closed eyes.

No mortality occurred.

Nickel did not significantly increase micronucleated PCEs at any dose level. Nickel was not significantly cytotoxic to bone marrow at any dose level.
Dose-dependent nickel concentrations were detected in plasma and bone marrow samples.

The author's suggest the results support the non-genotoxic mode of action for soluble nickel.

Applicant's summary and conclusion

Conclusions:

The test article, nickel sulfate hexahydrate, was evaluated as negative in the rat bone marrow micronucleaus assay under the conditions of this assay.

Executive summary:

STUDY RATED BY AN INDEPENDENT REVIEWER.