Abstract In the mouse lymphoma forward mutation assay@ in vitro treatments of the mouse lymphoma cell line@ L5178Y@ with API #83-05 induced significant Increases in the mutant frequency at the thymidine kinase (TK) locus only in the presence of metabolic activation. The cells were exposed to API #83-05 for four hours In the presence and absence of rat liver S9 metabolic activation. The test material was soluble at the concentrations tested. Under nonactivation conditions@ the test material was assayed from 5.25 nl/ml to 100 nl/ml and low to moderate toxicities were induced without inducing significant@ dose-dependent increases above the background mutation frequency. Treatment with 150 nl/ml was excessively toxic and not analyzable. In the presence of metabolic activation@ the test material was converted to a more active form or forms. Treatments from 18.8 nl/ml to 200 nl/ml induced repeatable Increases in the mutant frequency that ranged from 2@1-fold to 4@2-fold above the background mutant frequency. API #83-05 was therefore evaluated as active in the mouse lymphoma cell system only in the presence of metabolic activation.
API PUBL 32-32459-1985 history
1985API PUBL 32-32459-1985 MUTAGENICITY EVALUATION OF CATALYTIC REFORMED NAPHTHA API #83-05 IN THE MOUSE LYMPHOMA FORWARD MUTATION ASSAY