[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: O A Safonova, T N Popova, L V Matasova, V G Artiukhov
• Journal: Biomeditsinskaia khimiia (Biomed Khim) 2005 May-Jun Vol. 51 Issue 3 Pg. 311-20 ISSN: 2310-6972 [Print] Russia (Federation)
• PMID: 16104394 (Publication Type: English Abstract, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Adenine Nucleotides
• Cations, Divalent
• Free Radicals
• Hydrogen Peroxide
• Malate Dehydrogenase
• Malate Dehydrogenase (NADP+)
• Glutathione

Topics

• Adenine Nucleotides (chemistry)
• Animals
• Cations, Divalent (chemistry)
• Cytoplasm (enzymology)
• Enzyme Activation
• Free Radicals (metabolism)
• Glutathione (chemistry)
• Hydrogen Peroxide (chemistry)
• Kinetics
• Lipid Peroxidation
• Luminescent Measurements
• Malate Dehydrogenase (antagonists & inhibitors, chemistry, metabolism)
• Malate Dehydrogenase (NADP+)
• Male
• Myocardial Ischemia (enzymology)
• Myocytes, Cardiac (enzymology)
• Oxidation-Reduction
• Rats