[Relation between the 7-ethoxyresorufin-O-deethylase activity of the liver microsomal monooxygenase system and the level of methylcholanthrene-induced form of cytochrome P-450].
Changes in the metabolic activity of 7-ethoxyresorufin in rat liver microsomes containing different amounts of cytochrome P-450 induced by 3-methylcholanthrene and other polycyclic hydrocarbons (P-450c) were studied. Using antibodies to cytochrome P-450c for the determination of the cytochrome P-450c content and its metabolic role, it was demonstrated that 7-ethoxyresorufin O-deethylation by the liver microsomal monooxygenase system is catalyzed exclusively by cytochrome P-450c. The rate of the substrate metabolism is correlated with the cytochrome P-450c content in microsomal membranes; the cytochrome P-450c activity does not depend on the cytochrome P-450c/NADPH-cytochrome P-450 reductase ratio. The experimental results suggest that the level of 7-ethoxyresorufin metabolism in liver microsomes can be regarded as a measure of the cytochrome P-450c content, whose function is associated with the stimulation of potential carcinogenic and toxic substances.
Grishanova
A Iu
AIu
Peregoedova
E L
EL
Mishin
V M
VM
Liakhovich
V V
VV
D000818:Animals; D019363:Cytochrome P-450 CYP1A1; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis / Q000378:metabolism*; D004790:Enzyme Induction; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000378:metabolism*; D008297:Male; D008748:Methylcholanthrene; D008862:Microsomes, Liver / Q000201:enzymology* / Q000378:metabolism; D010078:Oxazines / Q000378:metabolism; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D065607:Cytochrome P-450 Enzyme Inhibitors; D007527:Isoenzymes; D010078:Oxazines; D008748:Methylcholanthrene; C007649:ethoxyresorufin; D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases; D019363:Cytochrome P-450 CYP1A1
Sootnoshenie mezhdu 7-étoksirezorufin-O-deétilaznoĭ aktivnost'iu mikrosomnoĭ monooksigenaznoĭ sistemy pecheni i kontsentratsieĭ metilkholantrenindutsiruemoĭ formy tsitokhroma P-450.