title: Coronary and myocardial effects of acetaminophen: protection during ischemia-reperfusion.
abstract: Acetaminophen is a phenol with antioxidant properties, but little is known about its actions on the mammalian myocardium and coronary circulation. We studied isolated, perfused guinea pig hearts, and tested the hypothesis that acetaminophen-treated hearts would be protected during ischemia-reperfusion. Acetaminophen concentrations in the range of 0.3-0.6 mmol/l caused modest but significant (P < 0.05) coronary vasoconstriction and positive inotropy. The effects were more brisk during constant pressure perfusion than during constant flow. During 20 min of low-flow, global myocardial ischemia and 40 min of reperfusion, hearts treated with acetaminophen retained or recovered a greater percentage of left ventricular function than hearts treated with vehicle. Myofibrillar ultrastructure appeared to be preserved in the reperfused myocardium with acetaminophen. By using chemiluminescence and spin-trap methodologies, we investigated acetaminophen-mediated antioxidant mechanisms to help explain the cardioprotection. The burst of hydroxyl radicals seen between 0 and 10 min of reperfusion was significantly attenuated (P < 0.05) by acetaminophen but not by vehicle. The 3-morpholinosydnominine (SIN-1) generation of peroxynitrite and its oxidative interaction with luminol to produce blue light during ischemia-reperfusion was also blocked by acetaminophen. Our results show that acetaminophen provides significant functional and structural protection to the ischemic-reperfused myocardium, and the mechanism of cardioprotection seems to involve attenuation of the production of both hydroxyl radicals and peroxynitrite.
authors.affiliation: Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey 08854-8082, USA. merrill@biology.rutgers.edu
authors.forename: G
authors.initials: G
authors.lastname: Merrill
authors.forename: P
authors.initials: P
authors.lastname: McConnell
authors.forename: K
authors.initials: K
authors.lastname: Vandyke
authors.forename: S
authors.initials: S
authors.lastname: Powell
mesh_terms: D000082:Acetaminophen / Q000494:pharmacology*; D000818:Animals; D003326:Coronary Circulation / Q000187:drug effects; D003331:Coronary Vessels / Q000187:drug effects; D019610:Cytoprotection / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005841:Gentisates; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D062385:Hydroxybenzoates / Q000378:metabolism; D017665:Hydroxyl Radical / Q000378:metabolism; D066298:In Vitro Techniques; D008163:Luminescent Measurements; D008297:Male; D017202:Myocardial Ischemia / Q000378:metabolism*; D015425:Myocardial Reperfusion; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D009206:Myocardium / Q000378:metabolism* / Q000648:ultrastructure; D009210:Myofibrils / Q000187:drug effects / Q000648:ultrastructure; D009566:Nitrates / Q000378:metabolism; D010477:Perfusion / Q000379:methods; D014661:Vasoconstriction / Q000187:drug effects; D016277:Ventricular Function, Left / Q000187:drug effects
chemical_list: D005841:Gentisates; D062385:Hydroxybenzoates; D009566:Nitrates; C039642:peroxynitric acid; D017665:Hydroxyl Radical; D000082:Acetaminophen; C010925:2,5-dihydroxybenzoic acid