[Effect of incorporation and removal of cholesterol on the lipid bilayer viscosity and the rate of oxidative reactions in rat liver microsomal membranes].
The interrelationship between the lipid bilayer viscosity and the rate of oxidative reactions in rat liver microsomal membranes were investigated. The viscosity of the lipid bilayer is increased upon incorporation of cholesterol into the microsomes and is decreased upon its removal. This results in a corresponding decrease and increase of the rate of cytochrome b5 reduction by NAD(P)H. The rates of cytochrome P-450 reduction and oxidation of dimethylaniline, aniline, p-nitroanisol and NAD(P)H, as well as those of oxygen uptake and lipid peroxidation do not depend on the bilayer viscosity. Hence only the reactions of cytochrome b5 reduction by NADH- and NADPH-specific flavoproteins are diffusion-dependent processes in the microsomal oxidation chain.
D000818:Animals; D002784:Cholesterol / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D003580:Cytochromes / Q000378:metabolism; D015786:Cytochromes b5; D007425:Intracellular Membranes / Q000378:metabolism*; D007700:Kinetics; D008051:Lipid Bilayers; D008297:Male; D008563:Membrane Lipids / Q000378:metabolism*; D008862:Microsomes, Liver / Q000378:metabolism*; D010084:Oxidation-Reduction; D051381:Rats; D014783:Viscosity
D003580:Cytochromes; D008051:Lipid Bilayers; D008563:Membrane Lipids; D015786:Cytochromes b5; D003577:Cytochrome P-450 Enzyme System; D002784:Cholesterol
Vliianie vstraivaniia i vyvedeniia kholesterina na viazkost' lipidnogo bisloia i skorost' okislitel'nykh protsessov v membranakh mikrosom pecheni Krysy.