title: Acetaminophen-mediated cardioprotection via inhibition of the mitochondrial permeability transition pore-induced apoptotic pathway.
abstract: Our laboratory has previously reported that acetaminophen confers functional cardioprotection following cardiac insult, including ischemia/reperfusion, hypoxia/reoxygenation, and exogenous peroxynitrite administration. In the present study, we further examined the mechanism of acetaminophen-mediated cardioprotection following ischemia/reperfusion injury. Langendorff-perfused guinea pig hearts were exposed to acute treatment with acetaminophen (0.35 mM) or vehicle beginning at 15 min of a 30-min baseline stabilization period. Low-flow global myocardial ischemia was subsequently induced for 30 min followed by 60 min of reperfusion. At the completion of reperfusion, hearts were homogenized and separated into cytosolic and mitochondrial fractions. Mitochondrial swelling and mitochondrial cytochromec release were assessed and found to be significantly and completely reduced in acetaminophen- vs. vehicle-treated hearts following reperfusion. In a separate group of hearts, ventricular myocytes were isolated and subjected to fluorescence-activated cell sorting. Acetaminophen-treated hearts showed a significant decrease in late stage apoptotic myocytes compared with vehicle-treated hearts following injury (58 +/- 1 vs. 81 +/- 5%, respectively). These data, together with electron micrograph analysis, suggest that acetaminophen mediates cardioprotection, in part, via inhibition of the mitochondrial permeability transition pore and subsequent apoptotic pathway.
authors.affiliation: Department of Cell Biology and Neuroscience, Division of Life Sciences, Rutgers University, 604 Allison Road, Piscataway, NJ 08854, USA.
authors.forename: Norell M
authors.initials: NM
authors.lastname: Hadzimichalis
authors.forename: Sunanda S
authors.initials: SS
authors.lastname: Baliga
authors.forename: Roseli
authors.initials: R
authors.lastname: Golfetti
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Jaques
authors.forename: Bonnie L
authors.initials: BL
authors.lastname: Firestein
authors.forename: Gary F
authors.initials: GF
authors.lastname: Merrill
mesh_terms: D000082:Acetaminophen / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002317:Cardiovascular Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002469:Cell Separation; D045304:Cytochromes c / Q000378:metabolism; D005434:Flow Cytometry; D006168:Guinea Pigs; D006439:Hemodynamics / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D008854:Microscopy, Electron; D008929:Mitochondria, Heart / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism / Q000648:ultrastructure; D033681:Mitochondrial Membrane Transport Proteins / Q000187:drug effects* / Q000378:metabolism; D000083162:Mitochondrial Permeability Transition Pore; D008933:Mitochondrial Swelling / Q000187:drug effects; D015428:Myocardial Reperfusion Injury / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism / Q000648:ultrastructure; D013997:Time Factors
chemical_list: D002317:Cardiovascular Agents; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D000082:Acetaminophen; D045304:Cytochromes c