ACTIVITY OF LIVER CYTOCHROME P-450-DEPENDENT MONOOXYGENASE SYSTEM IN MORPHINE-DEPENDENT RATS

Young female Wistar rats were injected intraperitoneally with increasi ng doses of morphine (9 - 45 mg/kg b.w. twice a day) for 14 days, The activities of the cytochrome P-450-dependent monooxygenase system and microsomal electron transport chain I were determined, Long-term morph ine treatment decreased significantly cytochrome P-450 content, while it did not affect microsomal electron transport chain I. A decrease in cytochrome bs content was accompanied by a compensatory increase in t he activity of NADH-cytochrome bs reductase, Both 4-aminopyrine N-deme thylase activity and aniline hydroxylase activity decreased after morp hine treatment (48% and 70%, respectively, when compared with controls ).