The free radical theory of aging postulates that the production of intracellular reactive oxygen species is the major determinant of life span. Numerous cell culture, invertebrate, and mammalian models exist that lend support to this half-century-old hypothesis. Here we review the evidence that both supports and conflicts with the free radical theory and examine the growing link between mitocho...

BACKGROUND An abnormal platelet release of oxygen-free radicals has been described in acetylsalicylic acid (aspirin)-induced asthma, a finding which might suggest the existence of an intrinsic, specific platelet abnormality of arachidonic acid metabolism in these patients. The objective of this study was to evaluate platelet arachidonic acid metabolism in asthmatic patients with or without into...

Crohn's disease and ulcerative colitis, known together as inflammatory bowel diseases (IBDs), and celiac disease are the most common disorders affecting not only adults but also children. Both IBDs and celiac disease are associated with oxidative stress, which may play a significant role in their etiologies. Reactive oxygen species (ROS) such as superoxide radicals (O2•-), hydroxyl radicals (•O...

Excessive stimulation of excitatory amino acid (EAA) receptors and abnormal production of oxygen-derived free radicals have repeatedly been implicated in the series of events linking brain hypoxia or ischemia to neuronal death. We report here that in rat hippocampal slices the KCl-stimulated output of labeled D-3H aspartate or of endogenous aspartate and glutamate significantly increased under ...

Human neutrophils generate oxygen reduction products as a consequence of membrane interactions with a number of stimuli. One oxygen-centered free radical (superoxide) has been unequivocally shown to result from this "respiratory burst," and some experimental evidence for another (hydroxyl radical) has been published, although debate remains as to its significance. The role of phagocyte-derived ...

For the reason of the biological importance of antioxidant enzymes and reactive oxygen species, it was deemed important to survey the literature for reports on the relation between them. The main aim of this overview not only uncovered the baseline works on aspects of prooxidant and antioxidant processes in different species, but also illuminated the mechanism of the free radical theory of agin...