title: Regulated production of free radicals by the mitochondrial electron transport chain: Cardiac ischemic preconditioning.
abstract: Excessive production of free radicals by mitochondria is associated with, and likely contributes to, the progression of numerous pathological conditions. Nevertheless, the production of free radicals by the mitochondria may have important biological functions under normal or stressed conditions by activating or modulating redox-sensitive cellular signaling pathways. This raises the intriguing possibility that regulated mitochondrial free radical production occurs via mechanisms that are distinct from pathologies associated with oxidative damage. Indeed, the capacity of mitochondria to produce free radicals in a limited manner may play a role in ischemic preconditioning, the phenomenon whereby short bouts of ischemia protect from subsequent prolonged ischemia and reperfusion. Ischemic preconditioning can thus serve as an important model system for defining regulatory mechanisms that allow for transient, signal-inducing, production of free radicals by mitochondria. Defining how these mechanism(s) occur will provide insight into therapeutic approaches that minimize oxidative damage without altering normal cellular redox biology. The aim of this review is to present and discuss evidence for the regulated production of superoxide by the electron transport chain within the ischemic preconditioning paradigm of redox regulation.
authors.affiliation: Free Radical Biology and Aging Program, Oklahoma Medical Research Foundation, Oklahoma City, 73104, United States.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Matsuzaki
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Szweda
authors.forename: Luke I
authors.initials: LI
authors.lastname: Szweda
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Humphries
mesh_terms: D042967:Electron Transport Complex I / Q000378:metabolism*; D005609:Free Radicals / Q000378:metabolism*; D006801:Humans; D019157:Ischemic Preconditioning, Myocardial; D008929:Mitochondria, Heart / Q000378:metabolism*; D033681:Mitochondrial Membrane Transport Proteins / Q000378:metabolism; D000083162:Mitochondrial Permeability Transition Pore; D008954:Models, Biological; D015428:Myocardial Reperfusion Injury / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D015221:Potassium Channels / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D005609:Free Radicals; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D015221:Potassium Channels; D017382:Reactive Oxygen Species; C117780:mitochondrial K(ATP) channel; D042967:Electron Transport Complex I