Increase in glucuronide conjugation of aflatoxin P1 after pretreatment with microsomal enzyme inducers.

Microsomes prepared from livers of chickens given enzyme inducers had increased capability to convert aflatoxin P1 to its glucuronide conjugate. This capability was 190% +/- 19 and 184% +/- 13 of control values (mean +/- S.E., N = 4) 96 h after intraperitoneal administration of 80 mg/kg beta-naphthoflavone or 3-methylcholanthrene, respectively. Glucuronidation of aflatoxin P1 was also increased 15 days after 500 mg/kg i.p. of a polychlorinated biphenyl mixture (to 471% +/- 111). Fifteen days on a low protein diet (containing 54% of normal levels) did not alter aflatoxin glucuronidation. Increased glucuronidation after administration of inducers was due to increased specific activity of the microsomal enzymes.