Low Carcinogenicity of the K-Region Epoxides of 7-Methylbenz(a)-anthracene and Benz (a) anthracene in the Mouse and Rat. ∗

Abstract

Summary

5,6-Epoxy-5,6-dihydro-7-methyl-benz (a) anthracene, a K-region epoxide of the carcinogenic hydrocarbon 7-methylbenz(a)-anthracene, had only low activity as a carcinogen in the subcutaneous tissues of the rat and mouse or in the skin of the mouse under conditions which permitted the parent hydrocarbon to exhibit moderate to high car-cinogenicity in these tissues. Likewise, 5,6-epoxy-5,6-dihydrobenz(a)anthracene or its 7-methyl derivative showed little or no activity as initiators of papilloma formation in mouse skin.