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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in mammalian cells
Remarks:
Type of genotoxicity: gene mutation
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
GLP-compliant, comparable to guideline study, available as unpublished report, minor restrictions in reporting, but otherwise adequate for assessment. Proof of the identity of the substance used in a study is the responsibility of the data owner of the study (internal company reference code 35109).

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report Date:
1988

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)
GLP compliance:
yes (incl. certificate)
Type of assay:
mammalian cell gene mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): 02511.01
- Physical state: clear liquid
- Storage condition of test material: room temperature

Method

Target gene:
TK locus
Species / strain
Species / strain / cell type:
mouse lymphoma L5178Y cells
Metabolic activation:
with and without
Metabolic activation system:
Aroclor-induced rat S9
Test concentrations with justification for top dose:
In the range-finding test: 0.1, 0.5, 1.0, 5.0, 10, 50, 100, 500, 1000 and 5000 μg/ml
In the main test: 50, 100, 300, 500, 700, 1000, 2500 and 5000 μg/ml
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: F0P, Fischer's Medium for leukemic cells of mice, supplemented with sodium piruvate, Pluronic P68, and penicyllin-strepromycin according to the Standard Operating Procedures of the test facility
- Justification for choice of solvent/vehicle: solvent of preference by the study sponsor
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: without S9: ethyl methanesulfonate, with S9: 7, 12-dimethylbens(a)anthracene
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium;

DURATION
- Exposure duration: 4 hours
- Expression time (cells in growth medium): 2 days
- Selection time (if incubation with a selection agent): at least 15 min


SELECTION AGENT (mutation assays): trifluorothymidine (TFT)

NUMBER OF REPLICATIONS: two

NUMBER OF CELLS EVALUATED: 3 x 10e6

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth
Evaluation criteria:
A response is considered positive if at least one culture has a mutation frequency that is two times or mroe greater than the average muitation frequency of the corresponding solvent control cultures and the response is dose-dependent. A response is considered equivocal if it does not fulfill the criteria of either a negative or a positive response, and/or the study director does not consider the response to be either positive or negative. A response is considered negative, if all of the cultures exhibiting total growth of 10% and greater have mutation frequencies that are less than twice that of the mean mutation frequencies of the corresponding solvent contol cultures, and there is no evidence of a dose-dependent response.

Results and discussion

Test results
Species / strain:
mouse lymphoma L5178Y cells
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
No toxicity was evident in any of the cultures in the range finding test. The culturres treated with 5000 μg/ml with and without S-9 had 93 and 98% relative suspension growth, respectively.
None of the cultures in the main test had mutation frequencies that were significantly greater than the mean mutation frequency of the solvent control cultures. The cultures treated without activation exhibited 88 to 104% relative total growth, and the cultures treated in conjunction with S9 exhibited 82 to101% relative total growth.
As expected, the cultures treated with the positive controls exhibited significant increases in mutation frequency relative to their solvent control cultures.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion