Effects of sex hormones on oncogenesis in rat urinary bladder by N-butyl-N-(4-hydroxybutyl)-nitrosamine.

The effects of testosterone propionate, estradiol, and estriol on the oncogenesis of male rats' bladder induced by oral administration of the carcinogen N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) were examined. There were significant differences between the testosterone propionate-administered and estradiol-administered groups and also between the testosterone propionate-administered and estriol-administered groups in the incidence of bladder tumors.