title: [Free-radical oxidation and regulation of cytoplasmic NADP-dependent malate dehydrogenase in rat cardiomyocytes at norm and under ischemia].
abstract: Experimental ishemia of rat myocardium was accompanied by increase of light sum (S) and maximal intensity (Imax) of chemiluminescence, amount of a malonic dialdehyde and conjugated dienes in cytoplasmic fraction. The activity of NADP-dependent malate dehydrogenase (EC 1.1.1.82; NADP-MDH) was 1.6 times higher in rat heart under ischemia. NADP-MDH was purified from normal and ischemia-exposed rat myocardium. Using NADP-MDH purified enzyme preparations the values of Hill coefficient for oxaloacetate (1.83 +/- 0.07 and 1.50 +/- 0.10) and Km for NADPH (0.058 +/- 0.003 and 0.096 +/- 0.004 mM) were determined for the enzyme at norm and under ischemia respectively. Effects of Fe2+, Ca2+, Cu2+ ions, H2O2, oxidized and reduced glutathione, adenine nucleotides influence on functioning of NADP-MDH from rat heart at norm and under ischemic conditions have been investigated.
authors.forename: O A
authors.initials: OA
authors.lastname: Safonova
authors.forename: T N
authors.initials: TN
authors.lastname: Popova
authors.forename: L V
authors.initials: LV
authors.lastname: Matasova
authors.forename: V G
authors.initials: VG
authors.lastname: Artiukhov
mesh_terms: D000227:Adenine Nucleotides / Q000737:chemistry; D000818:Animals; D002413:Cations, Divalent / Q000737:chemistry; D003593:Cytoplasm / Q000201:enzymology; D004789:Enzyme Activation; D005609:Free Radicals / Q000378:metabolism; D005978:Glutathione / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D007700:Kinetics; D015227:Lipid Peroxidation; D008163:Luminescent Measurements; D008291:Malate Dehydrogenase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D050538:Malate Dehydrogenase (NADP+); D008297:Male; D017202:Myocardial Ischemia / Q000201:enzymology*; D032383:Myocytes, Cardiac / Q000201:enzymology*; D010084:Oxidation-Reduction; D051381:Rats
chemical_list: D000227:Adenine Nucleotides; D002413:Cations, Divalent; D005609:Free Radicals; D006861:Hydrogen Peroxide; D008291:Malate Dehydrogenase; D050538:Malate Dehydrogenase (NADP+); D005978:Glutathione