Superoxide and nitric oxide induced nitrosative processes may follow unusual and different dynamic behaviors

by José Carlos Toledo

Possibly, most pathophysiological processes involving the radicals nitric oxide (NO•) and superoxide (O₂•–) depend on their simultaneous production and their favorable co-reaction to produce peroxynitrite. Peroxynitrite is an oxidant itself but in the presence of carbon dioxide it gives origin to radical species such as carbonate anion (CO₃•–) and nitrogen dioxide (NO₂•) radicals, both capable of stimulating oxidative and nitrosative events that damage biomolecules. The interplay of NO• and O₂•– in biological environments is complex, though. Using a fluorescent probe molecule to

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Succinate accumulates during ischemia forcing mitochondrial complex I to operate in reversal, while producing oxidant species during reperfusion

by José Carlos Toledo

Ischemia-reperfusion (IR) is a process where blood supply (thus oxygen supply) to an organ is interrupted and then restored. While reperfusion is essential for survival, it is accompanied by a burst of mitochondrial generation of redox species and intermediates such as superoxide and hydrogen peroxide. Such species associate with derived ischemic tissue injury, underling disorders such as heart attack and stroke [1]. Nonetheless, IR mitochondrial ROS production has been considered a nonspecific consequence of a dysfunctional interaction of mitochondrial redox

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