Triggering and modulation of apoptosis by oxidative stress

Cell survival requires multiple factors, including appropriate proportions of molecular oxygen and various antioxidants. Although most oxidative insul ts can be overcome by the cell's natural defenses, sustained perturbation o f this balance may result in either apoptotic or necrotic cell death. Numer ous, recent studies have shown that the mode of cell death that occurs depe nds on the severity of the insult. Oxidants and antioxidants can not only d etermine cell fate, but can also modulate the mode of cell death. Effects o f oxidative stress on components of the apoptotic machinery may mediate thi s modulation. This review will address some of the current paradigms for ox idative stress and apoptosis, and discuss the potential mechanisms by which oxidants can modulate the apoptotic pathway. (C) 2000 Elsevier Science Inc .