Metabolism of aflatoxin B1 to aflatoxins Q1, M1 and P1 by mouse and rat.

We have used a microtechnique to study (a) the metabolism of aflatoxin (AF)B1 by rat and mouse, and (b) the effect of phenobarbital treatment in vivo on the in vitro metabolism of AFB1 by hepatic microsomes from rat and mouse. The results indicate and AFP1, the O-demethylated product of AFB1, is a major metabolite produced by the mouse. Although it is detectable in rat, the amount produced is negligible and was calculated to be at least 10 times less than that produced by the mouse. Using several microincubations, AFP1 was prepared in sufficient quantities to verify its identity by UV spectroscopy and by thin layer chromatography against an authentic standard in six different solvent systems. Phenobarbital pretreatment resulted in an enhancement in the total metabolism of AFB1 as well as in the formation of AFM1, AFQ1 and AFP1.