Laboratory methods for ten hepatic toxification/detoxification parameters.
This article is a summary of laboratory methods for the hepatic drug metabolizing enzymes which are reliable, sensitive, and reasonably straightforward to perform. Assay conditions are given for which the enzyme rate determinations are linear with respect to time and protein concentration for hepatic tissue preparations from Charles River Sprague Dawley CD male rats. In selecting these particular assay methods, factors such as disposal of radioactive wastes, safety of laboratory personnel, and cost of required equipment were considered. Thus 9 of the 10 hepatic parameters utilize simple spectrophotometric techniques; the remaining assay (ethoxyresorufin O-deethylase) requires a spectrophotofluorometer. The hepatic toxification/detoxification assays are cytochrome P-450 and reduced glutathione content, NADPH-cytochrome C reductase, aminopyrine N-demethylase, ethoxyresorufin O-deethylase, glutathione S-transferase (3 substrates) and UDP-glucuronyltransferase (2 substrates).
D000633:Aminopyrine N-Demethylase / Q000378:metabolism; D000818:Animals; D001711:Biotransformation; D019363:Cytochrome P-450 CYP1A1; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D014453:Glucuronosyltransferase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D008658:Inactivation, Metabolic; D008099:Liver / Q000201:enzymology / Q000378:metabolism*; D009251:NADPH-Ferrihemoprotein Reductase / Q000378:metabolism; D010088:Oxidoreductases / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values
D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases; D019363:Cytochrome P-450 CYP1A1; D000633:Aminopyrine N-Demethylase; D009251:NADPH-Ferrihemoprotein Reductase; D014453:Glucuronosyltransferase; D005982:Glutathione Transferase