Species differences in the metabolism of aflatoxin B1.

The metabolism of aflatoxin B1 in a number of animals was investigated. Aflatoxin B1 is metabolized relatively more slowly in liver slices of sheep than in the mouse, goat, guinea-pig, rabbit and golden hamster. The rate of metabolism of the toxin by the 10,000 g supernatant is faster than the metabolism by liver slices. This may be as a result of the substrate not penetrating the liver cells readily. Species difference exist in the in vitro metabolism of aflatoxin B1 by hydroxylation and demethylation. The sheep and White Rock cockerel demethylate aflatoxin B1 poorly but the dog and duck do not demethylate the toxin at all. Of the animals studied, the duck, mouse and White Rock cockerel do not produce aflatoxin M1 at all. The sheep and dog produce aflatoxin M1 in comparatively large amounts, while the rat, goat and golden hamster produce aflatoxin M1 in smaller quantities.