[Mutagenicity test of halopredone acetate]

The mutagenicity of halopredone acetate (THS-201) was investigated by means of reverse mutation test in seven bacterial strains (S. typhimurium TA100, TA1535, TA98, TA1538, TA1537 and E. coli WP2, WP2 uvrA) and chromosomal aberration test in cultured Chinese hamster cells (CHL). In the reverse mutation test, no significant increase of revertant was observed at dose levels from 50 to 5000 micrograms/plate in the absence and presence of mammalian metabolic activation system. THS-201 caused no increase of chromosomal aberrants at dose levels of 1.6, 8.0, 40.0 and 200 micrograms/ml irrespective of metabolic activation. These results indicated that THS-201 has no mutagenic activity.