Year: 1986
Type: article
Abstract: A GROWING NUMBER of articles purport to demon- strate the importance of oxygen free radicals in a variety of pathophysiologic processes, including injury due to radiation, inflammation, and oxygen toxicity.The purpose of this essay is to examine the hypothesis that activated oxygen species may play a role in the extension of myocardial injury due to ischemia fol- lowed by reperfusion.Activated oxygen species include-superoxide anion, hydrogen peroxide, and hydroxyl radical.By virtue of an unpaired electron, they react with virtually all cell components, especially the sulfhydryl-containing ami- no acids and the unsaturated fatty acids.The potential consequences of unimpeded free-radical reactions in- clude denaturation of proteins, peroxidation of mem- brane lipids, generation of chemotactic factors, and impairment of collagen synthesis.As a result, there may be a loss of enzyme activity, disturbed membrane permeability, and increased inflammatory cell infiltra- tion.The intracellular defenses against oxygen radi- cal-mediated tissue damage include superoxide dis- mutase (SOD), an enzyme that catalyzes dismutation of superoxide anion to hydrogen peroxide.Two addi- tional cytoplasmic enzymes, catalase (CAT) and glutathione peroxidase, degrade hydrogen peroxide to water and oxygen.
Source: Circulation
Authors: S W Werns, M J Shea, B R Lucchesi
Institution: University of Michigan
Language: English
Subfield: Cardiology and Cardiovascular Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2060933702