Sex dependence of the metabolic activation in vitro of the mycohepatocarcinogen aflatoxin B1.

Using liver microsomes, metabolic activation of aflatoxin B1, determined by the formation of DNA- and protein-binding metabolites, was studied in an effort to elucidate the possible basis underlying sex differences in sensitivity of the male and female rat to aflatoxin B1. Male rats, which are more sensitive to AFB1, produced significantly higher amounts of these metabolites than female rats; castration of the male reduced the level to that of the female, whereas ovariectomy was without any effect.