Nickel(2+) diammonium 2,2',2'',2'''-(ethane-1,2-dinitrilo)tetraacetate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1983

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study without detailed documentation.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1985

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Ames test

Principles of method if other than guideline:

According to Ames et al. 1975

GLP compliance:

not specified

Type of assay:

other: bacterial reverse mutation assay

Test material

Test material information

1

Reference substance name:

Nickel sulphate

EC Number:

232-104-9

EC Name:

Nickel sulphate

Cas Number:

7786-81-4

Molecular formula:

H2O4S.Ni

IUPAC Name:

Nickel (II)sulphate

Specific details on test material used for the study:

Stock solutions of chemicals were prepared at 0.1 or 0.01 M concentrations in double glass-distilled water, sterilized by membrane filtration, and held in sealed glass bottles at room temperature. Aliquots of these stock solutions were used for mutagenicity assays at nontoxic concentrations. At the time of assay, serial half-log dilulions of each test chemical were prepared in distilled water.

Method

Target gene:

Reverse mutation

Species / strain

Species / strain / cell type:

other: S. typhimurium strains TA98, TA100, TA1535, TA1537, and TA1538 and E.Coli strain (DG1153)

Remarks:

Salmonella strains TA98, TA100, TA1535, TA1537, and TA1538 wete obtained from Professor B. N. Ames and The E. coli strain (DG1153) was obtained from Dr. D. G. MacPhee (La Trobe University)

Vehicle / solvent:

Double distilled water

Controls

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

not specified

Details on test system and experimental conditions:

PLATE INCORPORATION ASSAY: Plastic petri dishes were filled with 25 ml autoclave sterilised minimal glucose agar medium. lnto each 2 ml of top agar was added 100 uL of the appropriate Salmonella strain from an ovemight broth culture, followed by 100 uL of test chemical, prepared in serial half·log worklng dilutions. The top agar was mixed and poured over the surface of a minimal agar plate. After the agar had set, plates were inverted and incubated at 37'C for 3-5 days. Unless stated otherwise, assay results ate those from plates incubated for 3 days. Colony numbers were determined manually and plates were examined microscopically for evidence of lawn toxicity and for colony appearance. Each assay was repeated at least once.
FLUCTUATION ASSAY: The microtiter fluctuation test was petformed according to the rnethod of Gatehouse (1978). Test chemical dilutions were added to 20-ml aroounts of prepared medium, to give the required final dilutlon. Then 1 ml of a 1/10 dilution of 3- to 4-hr broth cultures of bacteria was added in each 20-ml test or control bottle, which was mixed and dispensed in 0.2-ml amounts into the 96 wells of Linbro/Titertek trays (Flow Laboratoties). Trays with Iids were tightly wrapped in plastlc to minimize evaporation and incubated at 37°C for 3 days. To determine bacterial growth, 20 uL of bromothymol blue (600 ug/ml) was added to each well: negative wells appeared blue-green and positive wells appeared ye!low. Where metals affected the color of the indicator dye, wells were assessed for turbidity, based on absorbance measurements in a MicroELISA Auto Reader (Dynatech Model MR580) at 630 nm.

Evaluation criteria:

The criteria for positive results were based on Ames, et al. (1975) and de Serres and Shelby (1979) and included : (1) a reproducible, dose-related increase in the number of revertant colonies and (2) a doubling of colony numbers on test plates compared with background control plates.

Statistics:

x2 test

Results and discussion

Test results

Key result

Species / strain:

other: S. typhimurium strains TA98, TA100, TA1535, TA1537, and TA1538 and E.Coli strain (DG1153)

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: not reported

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Additional information on results:

Nickel sulfate was found not to be mutagenic.

Remarks on result:

other: all strains tested

Applicant's summary and conclusion

Conclusions:

Nickel sulphate was found not to be mutagenic in the reverse mutation assay using S. typhimurium strains TA98, TA100, TA1535, TA1537, and TA1538 and E.Coli strain (DG1153).