NADPH-dependent reduction of amaranch in liver microsomes characterized the quantity of low spin forms of cytochrome P-450.
We confirmed that NADPH-dependent anaerobic amaranch reduction in rat liver microsomes is compatible with the interaction of the dye with Fe(III) heme of cytochrome P-450 as the type II substrate. This process is rate-limiting in the whole reaction. High positive correlation (r = 0.949) between the values of Vmax for reaction of NADPH-dependent anaerobic amaranch reduction and the relative content low spin forms of cytochrome P-450 determined by ESR in microsomes from liver of control and induced by PB, BP, IS and 4-MP rats was observed. Relative content of low spin forms of cytochrome P-450 determined by ESR was increased according to BP less than PB less than control less than IS approximately 4-MP; Vmax values increased according to BP less than PB less than control less than IS less than 4-MP. Thus, reaction of NADPH-dependent anaerobic amaranch reduction may be used for determination of low spin forms of cytochrome P-450 at physiological conditions.
Shcherbakov
V M
VM
Research Center of Molecular Diagnostics, USSR Ministry of Health, Moscow.
Dubrov
Y N
YN
Korneva
E N
EN
Molchanova
L D
LD
Semenov SYu
Devichensky
V M
VM
D000548:Amaranth Dye / Q000378:metabolism*; D000818:Animals; D001564:Benzo(a)pyrene / Q000008:administration & dosage; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D000077604:Fomepizole; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology*; D009249:NADP; D010084:Oxidation-Reduction; D010634:Phenobarbital / Q000008:administration & dosage; D011720:Pyrazoles / Q000008:administration & dosage; D051381:Rats; D011919:Rats, Inbred Strains; D012451:Safrole / Q000008:administration & dosage
D011720:Pyrazoles; D001564:Benzo(a)pyrene; D009249:NADP; D000077604:Fomepizole; D003577:Cytochrome P-450 Enzyme System; D000548:Amaranth Dye; D012451:Safrole; C015959:isosafrole; D010634:Phenobarbital