A Comparative Study on Aflatoxin B1 Metabolism in Mice and Rats

• Published in: British journal of cancer Vol. 25; no. 2; pp. 291 - 297
• Main Authors: Steyn, M, Pitout, M J, Purchase, I F H
• Format: Journal Article
• Language: English
• Published: Nature Publishing Group 01.06.1971
• ISSN: 0007-0920; 1532-1827
• DOI: 10.1038/bjc.1971.37

In vivo metabolic studies on rats and mice revealed a marked difference in the fluorescent compounds produced after ingestion of aflatoxin B 1 . The mouse converted aflatoxin B 1 to three unknown fluorescent compounds, designated x 1 , x 2 and x 3 and the known aflatoxin M 1 , while the rat was only capable of producing aflatoxin M 1 . The results suggested that metabolites x 1 , x 2 , x 3 and aflatoxin M 1 were not part of a major metabolic pathway, but produced independently. These unknown yellowish-green fluorescent compounds did not seem to be conjugated with sulphate or glucuronic acid. In vitro incubations of various mouse liver cell fractions with aflatoxin B 1 showed that metabolites x 1 , x 2 , x 3 and aflatoxin M 1 , could only be produced by the microsomal fraction and that NADPH was needed as a co-factor. The differences in aflatoxin metabolism by mice and rats are discussed in relation to the apparent resistance of the mouse to the carcinogenic effects of this toxin.