Abstract In the mouse lymphoma forward mutation assay@ in vitro treatments of the mouse lymphoma cell line L5178Y@ with API #83-07 induced significant increases in the mutation frequency at the thymidine kinase (TK) locus only in the presence of metabolic activation. The cells were exposed to API #83-07 for four hours in the presence and absence of rat liver S9 metabolic activation and the test material was soluble up to 50 nl/ml. Under nonactivation conditions@ API #83-07 was assayed at an applied concentration range of 5 nl/ml to 60 nl/ml without inducing significant increases in the mutant frequency. Nondetectable to moderate toxicities were induced and a small increase in concentration from 60 nl/ml to 80 nl/ml was excessively toxic and the treatment could not be cloned. In the presence of the metabolic activation mix@ API #83-07 was assayed from 2.5 nl/ml to 25 nl/ml and significant dose-dependent increases in the mutant frequency were induced above 5.0 nl/ml where low to very high toxicities were induced. API #83-07 was therefore evaluated as active in the mouse lymphoma cell system only in the presence of metabolic activation.
API PUBL 32-32167-1985 history
1985API PUBL 32-32167-1985 MUTAGENICITY EVALUATION OF 83-07 IN THE MOUSE LYMPHOMA FORWARD MUTATION ASSAY