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Toxicological information

Genetic toxicity: in vitro

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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:
not stated
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Not to current international guidelines, but scientifically acceptable

Data source

Reference
Reference Type:
publication
Title:
Cyto- and genotoxic effects of coordination complexes of platinum, palladium and rhodium in vitro
Author:
Bunger J. et al.
Year:
1996
Bibliographic source:
International Archives of Environmental Health, 69, 33-38

Materials and methods

Test guideline
Guideline:
other: Revised test protocol of Maron and Ames (1983)
Version / remarks:
The study differed principally from OECD TG471 in that only four bacterial strains were tested. The recommended strain TA1535 was ommitted.
Principles of method if other than guideline:
Bacterial reverse mutation assay. The study differed principally from OECD TG471 in that only four bacterial strains were tested. The recommended strain TA1535 was ommitted.
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Reference substance name:
Reference substance 001
Cas Number:
15336-18-2
Details on test material:
Ammonium hexachlororhodate (CAS 15336-18-2)

Method

Species / strain
Species / strain / cell type:
S. typhimurium, other: TA97a, TA98, TA100 and TA102
Metabolic activation:
with and without
Metabolic activation system:
Sprague-Dawley rat liver, Induced with Phenobarbital and beta-naphthoflavone
Test concentrations with justification for top dose:
The test substance was dissolved in distilled water and diluted to 5-500 ug/plate [probably 10, 50, 100 or 500 ug/plate] in all four tester strains , in the absence or presence of (4% and 10%) S9. The number of revertant colonies on the plates were recorded after 48 hours of incubation in the dark at 37degC.
Controlsopen allclose all
Negative solvent / vehicle controls:
yes
Remarks:
Distilled water
Positive controls:
yes
Positive control substance:
methylmethanesulfonate
Positive controls:
yes
Positive control substance:
other: 2-aminofluorene
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48 hr in dark

NUMBER OF REPLICATIONS: Tests done in duplicate and repeated at least three times
Evaluation criteria:
For the test substance to be considered mutagenic, a two-fold (or more) increase in the mean revertant numbers must be observed in the plates containing the test substanced compared to the spontaneous reversion rate.

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium, other: TA97a, TA98, TA100 and TA102
Metabolic activation:
with
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Species / strain:
S. typhimurium, other: TA97a, TA98 and TA102
Metabolic activation:
without
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Species / strain:
S. typhimurium, other: TA100
Metabolic activation:
without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Additional information on results:
The test substance caused a 2- to 10-fold increase in revertants in all four tester strains (compared with spontaneous reversion rates), in the presence of S9. In the absence of S9, a 2- to 10-fold increase in reversion rates was seen in three tester strains, whereas in TA100 there was no evidence of a mutagenic effect. "The increase in reverse mutation rates in the samples that tested positive was dosage-dependent".

Any other information on results incl. tables

High doses of the metal compounds proved toxic to the tester strains", resulting in a thinning of the background bacterial lawn. Although no actual data were provided for ammonium hexachlororhodate, the minimum toxic dose for the rhodium salts was apparently 500 ug/plate.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
positive

Ammonium hexachlororhodate was mutagenic in a bacterial reverse mutation assay using Salmonella typhimurium strains TA97a, TA98, TA100 and TA102 when tested in the presence and absence of a rat liver metabolic activation system.
Executive summary:

In a bacterial reverse mutation assay,similar to OECD Test Guideline 471, ammonium hexachlororhodate was tested for mutagenic activity using Salmonella typhimurium strains TA97a, TA98, TA100 and TA102 in both the presence and absence of a metabolic activation system derived from phenobarbital and beta-naphthoflavone induced rat livers (S9). (The recommended strain TA1535 was omitted.) A mutagenic effect was seen in all four strains in the presence of metabolic activation and in all but strain TA100 in its absence.

 

In conclusion, the test substance was mutagenic in Salmonella typhimurium, in the presence and absence of metabolic activation.