Oxidative modification of rat cardiac mitochondrial membranes and myofibrils by hydroxyl radicals.
The effect of hydroxyl radicals generated by the FeSO4/H2O2 system on structural properties of proteins and membranes was studied in rat cardiac mitochondria and myofibrils. Exposure of mitochondria to 0.1 mmol/l FeSO4/EDTA plus 1 mmol/l H202 at 37 degrees C for 30 or 60 min caused conjugated diene formation, but it was not accompanied by accumulation of fluorescent lipid-protein conjugates. On the other hand, fluorescence measurements revealed radical-induced and time-dependent loss of tryptophans and production of bityrosines. Under the same conditions, the gradual decrease in tryptophan flurescence and increase in bityrosine formation was also observed in radical-treated myofibrils. These results suggest that *OH radicals can alter the mitochondrial and myofibrillar function via oxidation of amino acid residues and might be implicated in the pathogenesis of myocardial injury.
Babusíková
E
E
Department of Biochemistry, Jessenius Faculty of Medicine, Comenius University, Martin, Slovakia.
Kaplán
P
P
Lehotský
J
J
Jesenák
M
M
Dobrota
D
D
D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D002478:Cells, Cultured; D005290:Ferric Compounds / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D017665:Hydroxyl Radical / Q000494:pharmacology*; D008297:Male; D008929:Mitochondria, Heart / Q000187:drug effects* / Q000378:metabolism*; D009210:Myofibrils / Q000187:drug effects / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism
D005290:Ferric Compounds; D017382:Reactive Oxygen Species; D017665:Hydroxyl Radical; C024823:ferric sulfate; D006861:Hydrogen Peroxide