Abstract: The activities and tissue distribution of cytochrome P450 drug-metabolizing enzyme were studied in liver,kidney,gill and muscle of allogynogenesis silver crucian carp Carassius auratus gibelio.Microsomal P450 and b5 contents were determined by the method of CO differential spectroscopy in liver,kidney,gill,intestine and muscle microsomes.Both cytochrome P450 and cytochrome b5 contents were found to be the maximum in liver microsome,and the minimum in muscle microsome.The activities of CYP2B,CYP3A and CYP2E were evaluated by microsomal N-demethylation of aminopyrine(APD),erythromycin(ERND)and 4-aniline-hydroxylation(AH)as probe specific reactions.The activities of APD(1.668±0.104)and ERND(0.941±0.061)nmol/(min·mg)were the maximum in liver microsome,and the minimum in muscle microsome[(0.245±0.011),and(0.078±0.019) nmol/(min·mg)].The maximal AH activity(0.052±0.009)nmol/(min·mg)was observed in liver microsome,but not be detected in muscle microsome,indicating that the above-mentioned cytochrome P450 isoenzymes were available in main tissue microsoms in the crucian carp,and the APD,ERND and AH activities were different in different tissues,the maximal activities being observed in liver microsome.
2011, Vol. 26 
