Enhancement of hepatic tumors induced by N-nitrosodimethylamine in female toads Bufo regularis by oestrone.

Abstract

The effect of oestrone on hepatic tumours induced in the female toads Bufo regularis by N-nitrosodimethylamine (DMNA) was evaluated. Injecting the toads with DMNA induced hepatocellular carcinomas in 17% comparable with 23% in toads injected with DMNA plus oestrone. These results show that oestrone insignificantly enhanced the tumour formation. Oestrone alone induced hepatic tumours in only 4 cases and was considered as a weak initiator.