title: Inhibition of Na⁺-H⁺ exchange as a mechanism of rapid cardioprotection by resveratrol.
abstract: BACKGROUND AND PURPOSE Resveratrol is a polyphenol abundantly found in grape skin and red wine. In the present study, we investigated whether resveratrol exerts protective effects against cardiac ischaemia/reperfusion and also explored its mechanisms. EXPERIMENTAL APPROACH Infarct size and functional recovery in rat isolated perfused hearts subjected to no-flow global ischaemia followed by reperfusion were measured. Cultured neonatal rat cardiomyocytes were exposed to H(2)O(2) (100 µmol·L(-1)) to induce cell injury. Intracellular ion concentrations were measured using specific dyes. Western blotting was used to quantify protein expression levels. KEY RESULTS In rat isolated perfused hearts, treatment with resveratrol (20 and 100 µmol·L(-1)) 15 min before ischaemia considerably improved left ventricular functional recovery and infarct size. In cultured neonatal rat cardiomyocytes, resveratrol significantly attenuated the increase in reactive oxygen species (ROS) and loss of mitochondrial inner membrane potential. Resveratrol also suppressed the increase in intracellular concentrations of Na(+) ([Na(+)](i)) and Ca(2+) ([Ca(2+)](i)) after H(2)O(2) application; however, it did not suppress the ouabain-induced [Ca(2+) ](i) increase. By measuring changes in intracellular pH recovery after acidification, we also confirmed that acid-induced activation of the Na(+)-H(+) exchanger (NHE) was prevented by pretreatment with resveratrol. Furthermore, resveratrol inhibited the H(2)O(2)-induced translocation of PKC-α from the cytosol to the cell membrane; this translocation is believed to activate NHE. CONCLUSION AND IMPLICATIONS Resveratrol exerts cardioprotection by reducing ROS and preserving mitochondrial function. The PKC-α-dependent inhibition of NHE and subsequent attenuation of [Ca(2+)](i) overload may be a cardioprotective mechanism.
authors.affiliation: Department of Laboratory Examination and Diagnostics, Faculty of Medicine, Oita University, Yufu City, Oita, Japan.
authors.forename: Luong Cong
authors.initials: LC
authors.lastname: Thuc
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Teshima
authors.forename: Naohiko
authors.initials: N
authors.lastname: Takahashi
authors.forename: Satoru
authors.initials: S
authors.lastname: Nishio
authors.forename: Akira
authors.initials: A
authors.lastname: Fukui
authors.forename: Osamu
authors.initials: O
authors.lastname: Kume
authors.forename: Shotaro
authors.initials: S
authors.lastname: Saito
authors.forename: Mikiko
authors.initials: M
authors.lastname: Nakagawa
authors.forename: Tetsunori
authors.initials: T
authors.lastname: Saikawa
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002316:Cardiotonic Agents / Q000494:pharmacology*; D002478:Cells, Cultured; D006352:Heart Ventricles / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D006861:Hydrogen Peroxide / Q000494:pharmacology; D066298:In Vitro Techniques; D053078:Membrane Potential, Mitochondrial; D015428:Myocardial Reperfusion Injury / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000502:physiology; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D000077185:Resveratrol; D012964:Sodium / Q000378:metabolism; D017923:Sodium-Hydrogen Exchangers / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013267:Stilbenes / Q000494:pharmacology*; D016276:Ventricular Function / Q000187:drug effects
chemical_list: D002316:Cardiotonic Agents; D017382:Reactive Oxygen Species; D017923:Sodium-Hydrogen Exchangers; D013267:Stilbenes; D012964:Sodium; D006861:Hydrogen Peroxide; D011493:Protein Kinase C; D000077185:Resveratrol; D002118:Calcium