title: Exercise preconditioning-induced late phase of cardioprotection against exhaustive exercise: possible role of protein kinase C delta.
abstract: The objective of this study was to investigate the late cardiac effect of exercise preconditioning (EP) on the exhaustive exercise-induced myocardial injury in rats and the role of protein kinase C (PKC) in EP. Rats were subjected to a run on the treadmill for four periods of 10 min each at 30 m/min with intervening periods of rest of 10 min as an EP protocol. The exhaustive exercise was performed 24 h after EP. PKC inhibitor chelerythrine (CHE) was injected before EP. The results showed that EP increased the running ability of rats, and alleviated the exhaustive exercise-induced injury in cardiomyocytes, but pretreatment with PKC inhibitor CHE did not abolish the late phase cardioprotection of EP. A significant increase of PKCδ, both at the protein level and the mRNA level in the left ventricular myocardium of rats, accompanied by its activated form (phosphorylated on Thr507, p-PKCδThr507) translocated to intercalated disks and was found in the late phase of EP. This circumstance was not attenuated by CHE. These results suggested that a high level of PKCδ might be involved in cardioprotection against myocardial damage, but if activated PKCδ at reperfusion took on a key role in cardioprotection was still an outstanding question.
authors.affiliation: Department of Sports Anatomy, School of Sports Science, Shanghai University of Sport, 399 Changhai Road, Shanghai, 200438, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Hao
authors.forename: Shan-Shan
authors.initials: SS
authors.lastname: Pan
authors.forename: Yu-Jun
authors.initials: YJ
authors.lastname: Shen
authors.forename: Jun
authors.initials: J
authors.lastname: Ge
mesh_terms: D000818:Animals; D053119:Benzophenanthridines / Q000378:metabolism; D002316:Cardiotonic Agents / Q000378:metabolism*; D006352:Heart Ventricles / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D017202:Myocardial Ischemia / Q000378:metabolism / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000378:metabolism / Q000502:physiology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051745:Protein Kinase C-delta / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D053119:Benzophenanthridines; D002316:Cardiotonic Agents; C016299:chelerythrine; D051745:Protein Kinase C-delta