KATP channels and myocardial preconditioning: an update.
Ischemic or myocardial preconditioning (IPC) is a phenomenon whereby brief periods of ischemia have been shown to protect the myocardium against a more sustained ischemic insult. The result of IPC may be manifest as a marked reduction in infarct size, myocardial stunning, or incidence of cardiac arrhythmias. Whereas many endogenous neurotransmitters, peptides, and hormones have been proposed to play a role in the signal transduction pathways mediating the cardioprotective effect of IPC, nearly universal evidence indicates the involvement of the ATP-sensitive potassium (KATP) channel. Initial evidence suggested that the surface or sarcolemmal KATP (sarcKATP) channel triggered or mediated the cardioprotective effects of IPC; however, more recent findings have suggested a major role for a mitochondrial site or possibly a mitochondrial KATP channel (mitoKATP). This review presents evidence that supports a role for these two channels as a trigger and/or downstream mediator in the phenomenon of IPC or pharmacologically induced PC as well as recent evidence that suggests the involvement of a mitochondrial calcium-activated potassium (mitoKca) channel or the electron transport chain in mediating the beneficial effects of IPC or pharmacologically induced PC.
Gross
Garrett J
GJ
Dept. of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Rd., Milwaukee, WI 53226, USA. ggross@mcw.edu
Peart
Jason N
JN
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D006801:Humans; D019157:Ischemic Preconditioning, Myocardial; D017202:Myocardial Ischemia / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism; D015221:Potassium Channels / Q000378:metabolism*
D015221:Potassium Channels; D000255:Adenosine Triphosphate