The detection of enzyme induction by rat liver microsomes prepared by isoelectric precipitation.
A comparison was made of various indices of the hepatic drug-metabolizing apparatus associated with the postmitochondrial superntant, microsomes harvested by differential centrifugation, and microsomes harvested by isoelectric precipitation from control, phenobarbitone-pretreated and 3-methylcholanthrene-pretreated rats. The metabolic capabilities and distinctions between control and induced rats for each of the three liver preparations compared favourably as determined by the concentration of cytochrome b5 and P-450 and by the activity of NADPH-cytochrome c reductase, 4-dimethylaminoantipyrine N-demethylase and aryl hydrocarbon (benzo[a]pyrene) hydroxylase. The results suggest that the relatively simple isoelectric precipitation technique is a useful alternative to the conventional method of differential centrifugation for the preparation of hepatic microsomes.
D000818:Animals; D001579:Benzopyrene Hydroxylase / Q000378:metabolism; D002499:Centrifugation, Density Gradient; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D003580:Cytochromes / Q000378:metabolism; D004790:Enzyme Induction / Q000187:drug effects; D007526:Isoelectric Point; D008099:Liver / Q000201:enzymology; D008297:Male; D008748:Methylcholanthrene / Q000494:pharmacology; D008862:Microsomes, Liver / Q000201:enzymology*; D009251:NADPH-Ferrihemoprotein Reductase / Q000378:metabolism; D010089:Oxidoreductases, N-Demethylating / Q000378:metabolism; D010634:Phenobarbital / Q000494:pharmacology; D051381:Rats
D003580:Cytochromes; D008748:Methylcholanthrene; D003577:Cytochrome P-450 Enzyme System; D001579:Benzopyrene Hydroxylase; D010089:Oxidoreductases, N-Demethylating; D009251:NADPH-Ferrihemoprotein Reductase; D010634:Phenobarbital