Generation of Oxygen Free Radicals by Proflavine: Implication in Protein Degradation

Protein Damage and Degradation by Oxygen Radicals

Aggregation, fragmentation, amino acid modification, and proteolytic susceptibility have been studied following exposure of 17 proteins to oxygen radicals. The hydroxyl radical (‘OH) produced covalently bound protein aggregates, but few or no fragmentation products. Extensive changes in net electrical charge (both + and -) were observed. Tryptophan was rapidly lost with ‘OH exposure, and signif...

Oxygen-Derived Free Radicals in Rats

Myocardial ischemia and reperfusion can evoke excitation of cardiac vagal afferent nerve endings and activation of a cardiogenic depressor reflex (Bezold-Jarisch effect). We postulate that oxygen-derived free radicals, which are well known to be produced during prolonged ischemia and reperfusion, contribute to this excitation. Hydroxyl radicals derived from hydrogen peroxide (H202) activate abd...

Modulation of fibroblast proliferation by oxygen free radicals.

The major unexplained phenomenon in fibrotic conditions is an increase in replicating fibroblasts. In this report we present evidence that oxygen free radicals can both stimulate and inhibit proliferation of cultured human fibroblasts, and that fibroblasts themselves release superoxide (O2.-) free radicals. Fibroblasts released O2.- in concentrations which stimulated proliferation, a finding co...

Biochemistry of Oxygen and Its Free Radicals

Thrombolytic treatment in acute myocardial infarction achieves coronary patency in most patients.' Mortality in groups treated early after the onset of symptoms is significantly reduced,' but left ventricular function does not always improve.5 Myocardial necrosis during the period of vessel occlusion is partly responsible for the irreversible ventricular impairment that occurs even when the ves...

Oxygen free radicals and retinopathy of prematurity.