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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:
experimental study
Adequacy of study:
key study
Study period:
not stated
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: This study was conducted prior to GLP and test guidelines, but sufficient data is available for interpretation of results

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1982

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)
Deviations:
yes
Remarks:
Only two doses were conducted and test was not conducted with metabolic activation.
GLP compliance:
no
Type of assay:
mammalian cell gene mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Epichlorohydrin (ECH) was obtained from Schuchardt, Munich, F.R.G.

Method

Target gene:
HPRT gene
Species / strain
Species / strain / cell type:
mouse lymphoma L5178Y cells
Details on mammalian cell type (if applicable):
No addtional information provided.
Additional strain / cell type characteristics:
not specified
Metabolic activation:
without
Test concentrations with justification for top dose:
0.0, 0.5 and 1mM
Vehicle / solvent:
no data
Details on test system and experimental conditions:
Mouse lymphoma ceIls
The cells were cultured in a humidified CO, incubator (5% CO,) at 37C in standard medium, Ham's F10 modified by the omission of hypoxanthine and
thymidine, and supplemented with 15% newborn calf serum (Gibco), penicillin G (100 U/ml) and streptomycin (0.1 mg/ml). For cloning, the standard medium was supplemented with 0.4% Noble agar. To select for cells with the HGPRT-deficient phenotype, the agar medium was supplemented with the purine analog 6-thioguanine (TG, 5 ug/ml) (Knaap and Simons, 1975).

In the mutagenesis assays, cells were exposed to the compound at the appropriate concentrations, for 2 h at 37C. After treatment, cells were washed and (a) seeded for survival, 150 cells per 15 ml of agar medium per P94 petri dish (5 dishes per group), and (b) propagated in Roux bottles for several days in standard medium to allow expression of the induced mutants that had resulted from the treatment (about 10(7) cells per group). During the expression time, cell counts were made daily (coulter counter) to keep record of cell growth, and according to these, cultures were diluted. At the end of the expression time, i.e. 7 days after treatment, cells were seeded for (a) cloning efficiency, 150 cells per 15 ml of agar medium per P94 petri dish (5 dishes per group), and (b) selection of mutants, 7.5 X 10(5) cells per 15 ml of selective medium per P94 petri dish (10 dishes per group). The
mutant frequency was calculated according to the following formula:

mutant frequency = (100/cloning efficiency) x (number of mutants/number of cells seeded)

Test was conducted in duplicate.
Evaluation criteria:
No additional information provided.
Statistics:
No data.

Results and discussion

Test results
Species / strain:
mouse lymphoma L5178Y cells
Metabolic activation:
without
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
not specified
Untreated negative controls validity:
valid
Positive controls validity:
not examined
Additional information on results:
At 0.5 mM, approximately 63.6% of the cells survived on day 0 while 18.1% of the cells exposed to 1.0 mM ECH survived on day 0. The induced mutant frequency was 2.0 and 4.0 x 10(5) at 0.5 and 1.0 mM, respectively. There was considerable variation is response at a specific concentration, i.e., at 0.5 mM, the induced mutant frequency was 2.8 and 1.2 x 10(5).

Any other information on results incl. tables

Epichlorohydrin was positive in L5178 mouse lymphoma cells without metabolic activation.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
positive without metabolic activation

Epichlorohydrin was positive in L5178 mouse lymphoma cells without metabolic activation.
Executive summary:

Epichlorohydrin was positive in L5178 mouse lymphoma cells without metabolic activation.