EFFECT OF THE FUNGICIDE IMAZALIL ON HEPATIC-MICROSOMAL CYTOCHROME-P-450 AND CYTOCHROME-P-450 DEPENDENT ACTIVITIES IN THE BOBWHITE QUAIL (COLINUS-VIRGINIANUS)

Bobwhite quails were treated with imazalil for 8 weeks. The fungicide was given admixed in the food at 0, 100, 300, 500 and 1000 mg kg−1. Even at the highest dose tested, imazalil did not affect the liver weight or the hepatic microsomal protein content. In treated quails, no significant induction of cytochrome P‐450 or NADPH‐cytochrome c‐reductase activity was observed. Furthermore, imazalil did not induce or inhibit 7‐ethoxyresorufin or 7‐ethoxycoumarin O‐deethylase in quail microsomes. Only a slight but significant increase by 35% and 49% in aniline hydroxylase activity was measured for the 500‐ and 1000‐mg kg−1 dose levels, respectively. After a drug‐free period of one week, aniline hydroxylase activity returned to control values, indicating that the effect was fully reversible. It is concluded that imazalil does not induce or inhibit drug‐metabolizing enzymes in the quail, even at doses which exceed by far the maximum levels currently used to dress seed under field conditions (100 mg kg−1). Copyright © 1990 John Wiley & Sons, Ltd