title: [Intermembrane electron transport in the dynamics of high-amplitude swelling of rat liver mitochondria].
abstract: The rate of rotenone insensitive NADH oxidation depending on the extent of rat liver mitochondria swelling in isotonic sucrose medium has been studied. The rate of exogenous NADH oxidation was determined fluorimetrically in the presence of 4 microM cytochrome c in the medium after the inhibition of high-amplitude swelling at its different stages by means of rotenone +Mg2+ + trifluoromethoxyphenylhydrasonecarbonylcyanide (FCCP) addition. Activation of external pathway of NADH oxidation in phosphate containing medium was conditioned by quick energy and phosphate-dependent mitochondria swelling that leads to the outer membrane disruption. An increase in the rate of NADH oxidation as a result of the outer membrane disruption during high amplitude swelling in isotonic sucrose medium has been shown to be nearly proportional to the extent of the decrease in optical density of mitochondria suspension. Similar decrease in optical density of homogenates incubated 25-30 min in isotonic sucrose medium was also accompanied by a significant increase in Mg(2+)-cytochrome c-dependent rotenone insensitive NADH oxidation. A decrease in optical density of liver homogenates was prevented by EGTA+2+, rotenone+Mg2++FCCP, rotenone or FCCP alone and was nearly completely inhibited at any stages of changes by means of rotenone+Mg2++FCCP addition that usually inhibit mitochondrial swelling. That means that the rate of Mg(2+)-cytochrome-c-dependent rotenone insensitive NADH oxidation in homogenates may be used as the simple method to evaluate the outer mitochondrial membrane disruption with the purpose to analyse the liver bioptate to study the effect of hormonal, xenobiotic and physical factors on mitochondrial macrostructure.
authors.forename: V V
authors.initials: VV
authors.lastname: Lemeshko
authors.forename: V E
authors.initials: VE
authors.lastname: Shekh
authors.forename: T V
authors.initials: TV
authors.lastname: Aleksenko
mesh_terms: D000818:Animals; D004579:Electron Transport; D004734:Energy Metabolism / Q000187:drug effects; D066298:In Vitro Techniques; D007425:Intracellular Membranes / Q000737:chemistry*; D007700:Kinetics; D008297:Male; D008930:Mitochondria, Liver / Q000737:chemistry*; D008933:Mitochondrial Swelling / Q000502:physiology*; D009243:NAD / Q000378:metabolism*; D010084:Oxidation-Reduction; D051381:Rats; D017208:Rats, Wistar; D012402:Rotenone / Q000494:pharmacology*; D014475:Uncoupling Agents / Q000494:pharmacology*
chemical_list: D014475:Uncoupling Agents; D012402:Rotenone; D009243:NAD