The fate of aflatoxin B₁ in animals

Abstract

The study of the fate of aflatoxin B₁ (AFB₁) in the rat demonstrated that the main site for the toxin absorption is the small intestine. AFB₁ transferred from the intestinal lumen almost exclusively into the mesenteric blood. The increase in the rate of absorption nearly in proportion to the increase in AFB₁ concentration in the medium suggests that AFB₁ is absorbed substantially by passive diffusion. After being absorbed from the intestine, AFB₁ enters exclusively into mesenteric vein and is partially converted to AFL by the blood cell. Comparison of the liver microsomal activity forming AFB₁-DNA adduct among various species showed no correlation between the activity and species difference in susceptibility to AFB₁ toxicity. However, a reverse relationship was observed between the liver cytosol glutathione-S transferase (GST) activity and species susceptibility, but no relationship was noted between the liver cytosol aldehyde reductase activity toward AFB₁ aldehyde activity and species susceptibility. The results indicated the importance of liver cytosol GST activity in species differences in susceptibility to AFB₁.