Cytochrome C effect on respiration of heart mitochondria: influence of various factors.
The effect of exogenous cytochrome c on respiration rate of the rat and human heart mitochondria was assessed in situ, using permeabilized fibers. It was (i) much more pronounced in State 2 and 4 than in State 3 with all the respiratory substrates (pyruvate+malate, succinate, palmitoyl-CoA+carnitine and octanoyl-L-carnitine), (ii) different with different substrates, (iii) much higher after ischemia in both metabolic states, particularly in the case of succinate oxidation compared to pyruvate+malate, (iv) the highest in State 4 with succinate as a substrate. Similar results were obtained with the isolated rat and rabbit heart mitochondria. The differences in the degree of stimulation of mitochondrial respiration by cytochrome c and, thus, sensitivity of cytochrome c test in evaluation of the intactness/injury of outer mitochondrial membrane are probably determined by the differences in the cytochrome c role in the control of mitochondrial respiration in the above-described conditions.
Toleikis
Adolfas
A
Institute for Biomedical Research, Kaunas University of Medicine, Eiveniu St.4, LT-50009, Kaunas-7, Lithuania.
Trumbeckaite
Sonata
S
Majiene
Daiva
D
D000818:Animals; D001278:Atractyloside / Q000494:pharmacology; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002331:Carnitine / Q000737:chemistry; D045304:Cytochromes c / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D008293:Malates / Q000737:chemistry; D008297:Male; D008928:Mitochondria / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism; D010101:Oxygen Consumption; D019308:Palmitic Acid / Q000737:chemistry; D010766:Phosphorylation; D019289:Pyruvic Acid / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar
D008293:Malates; D001278:Atractyloside; D019308:Palmitic Acid; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; C030298:malic acid; D019289:Pyruvic Acid; D045304:Cytochromes c; D002331:Carnitine; D010100:Oxygen