Exercise preconditioning provides early cardioprotection against exhaustive exercise in rats: potential involvement of protein kinase C delta translocation.
The objective of this study was to investigate the early cardioprotective effect of exercise preconditioning (EP) on the exhaustive exercise-induced myocardial injury in rats and the role of protein kinase C delta isoform (PKCδ) in EP. Rats were subjected to 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 0.5 h after EP. PKC inhibitor chelerythrine (CHE) was injected before EP. Our results showed that EP markedly attenuated the exhaustive exercise-induced myocardial ischemia/hypoxia, ultrastructural damage, high serum cTnI, and NT-proBNP levels. CHE injection before EP did not abolish the protection of EP. Both exhaustive exercise and EP produced a significant increase in PKCδ and p-PKCδ(Thr507) protein levels in cardiomyocytes. However, the immunostaining of p-PKCδ(Thr507) in EP cardiomyocytes was primarily localized to intercalated disks and nuclei while the exhaustive exercise-induced high level p-PKCδ(Thr507) was mainly distributed in the cytoplasm. Moreover, the high PKCδ and p-PKCδ(Thr507) levels in exhaustive exercise were significantly down-regulated by EP. CHE did not attenuate the expressions of PKCδ and p-PKCδ(Thr507). These results indicate that an appropriate activation and translocation of PKCδ may represent a mechanism whereby EP can exert an early cardioprotection against exhaustive exercise-induced myocardial injury.
Department of Sports Anatomy, School of Sports Science, Shanghai University of Sport, Shanghai 200438, China.
Yu-Jun
YJ
Shen
Shan-Shan
SS
Pan
Jun
J
Ge
Zhe
Z
Hao
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D053119:Benzophenanthridines / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D008297:Male; D009124:Muscle Proteins / Q000378:metabolism*; D017202:Myocardial Ischemia / Q000209:etiology / Q000378:metabolism*; D010805:Physical Conditioning, Animal / Q000009:adverse effects*; D051745:Protein Kinase C-delta / Q000037:antagonists & inhibitors / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D000970:Antineoplastic Agents; D053119:Benzophenanthridines; D009124:Muscle Proteins; C016299:chelerythrine; C497260:Prkcd protein, rat; D051745:Protein Kinase C-delta