Simultaneous inhibition of liver carcinogenicity and enhancement of bladder carcinogenicity of N-2-fluorenylacetamide by butylated hydroxytoluene.

The effect of butylated hydroxytoluene on the carcinogenicity to rats of concurrently administered N-2-fluorenylacetamide was determined. N-2-Fluorenylacetamide at 200 ppm alone in the diet produced liver neoplasms but no bladder neoplasms after 25 weeks. With simultaneous administration, 6000 ppm butylated hydroxytoluene inhibited the induction of liver neoplasms but resulted in production of bladder neoplasms. The finding that butylated hydroxytoluene inhibited hepatocarcinogenesis by N-2-fluorenylacetamide but enhanced bladder carcinogenesis demonstrates the complexity of potential effects on chemical carcinogenesis produced by modifying agents.