Mechanisms of myocardial reperfusion injury.
Reperfusion of the ischemic myocardium results in irreversible tissue injury and cell necrosis, leading to decreased cardiac performance. While early reperfusion of the heart is essential in preventing further tissue damage due to ischemia, reintroduction of blood flow can expedite the death of vulnerable, but still viable, myocardial tissue, by initiating a series of events involving both intracellular and extracellular mechanisms. In the last decade, extensive efforts have focused on the role of cytotoxic reactive oxygen species, complement activation, neutrophil adhesion, and the interactions between complement and neutrophils during myocardial reperfusion injury. Without reperfusion, myocardial cell death evolves slowly over the course of hours. In contrast, reperfusion after an ischemic insult of sufficient duration initiates an inflammatory response, beginning with complement activation, followed by the recruitment and accumulation of neutrophils into the reperfused myocardium. Modulation of the inflammatory response, therefore, constitutes a potential pharmacological target to protect the heart from reperfusion injury. Recognition of the initiating factor(s) involved in myocardial reperfusion injury should aid in development of pharmacological interventions to selectively or collectively attenuate the sequence of events that mediate extension of tissue injury beyond that caused by the ischemic insult.
Park
J L
JL
Department of Pharmacology, University of Michigan Medical School, Ann Arbor 48109-0632, USA.
Lucchesi
B R
BR
D000818:Animals; D002470:Cell Survival / Q000502:physiology; D003167:Complement Activation / Q000502:physiology; D006801:Humans; D009200:Myocardial Contraction / Q000502:physiology; D015428:Myocardial Reperfusion Injury / Q000503:physiopathology*; D018375:Neutrophil Activation / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism; D018746:Systemic Inflammatory Response Syndrome / Q000503:physiopathology
D017382:Reactive Oxygen Species