Effect of Protein Kinase C on Expression of SUR2A Subunit of ATP-sensitive Potassium Channel in Myocardial Sarcolemma during Early Exercise Preconditioning
XU Bai-chao
WANG Kai
Abstract：Objective To investigate the effect of protein kinase C (PKC) on the expression of SUR2 A subunit of ATP-sensitive potassium channel in myocardium during early exercise preconditioning. Methods Thirty-two healthy male SD rats were selected and trained at a speed of 15 m/min for 5 days on the experimental treadmill. They were divided into control group, exhaustive exercise group (EE group), early exercise pretreatment + exhaustive exercise group (EEP + EE group) and protein kinase C (PKC) blocker + early exercise pretreatment + exhaustive exercise group (CHE + EEP + EE group), with 8 rats in each group. The control group did not undergo any treadmill training. In EE group, exhaustive exercise training was conducted at a speed of 35 m/min to establish a rat model of exercise-induced myocardial injury. In EEP + EE group, the EEP animal model was established by 10-min exercise at a speed of 28-30 m/min, and 10-min rest, which was repeated four times. After 30 min, the EEP animal model was trained at a speed of 35 m/min until exhaustion. CHE + EEP + EE group received intraperitoneal injection of 5 mg/kg chelerythrine before exercise. The remaining the exercise methods were identical with those of EEP + EE group. The expression of SUR2 A in myocardium was detected. Results Compared with the control group, the positive reaction area and integral optical density of SUR2 A in situ hybridization in EE group were increased, and the expression levels of SUR2 A mRNA and SUR2 A in EE group and CHE+EEP+EE group were increased, suggesting significant difference (P＜0.05). Compared with EE group, the positive reaction area and integral optical density of SUR2 A in situ hybridization in EEP+EE group were decreased, and the expression levels of SUR2 A mRNA and SUR2 A were both increased, indicating significant differences (P＜0.05). The positive reaction area and integral optical density of SUR2 A mRNA in CHE+EEP+EE group were increased, and the expression levels of SUR2 A mRNA and SUR2 A were increased in CHE+EEP+EE group compared with EEP+EE group (P＜0.05). There were significant differences (P＜0.05). Conclusion PKC protects myocardium by regulating the expression of SUR2 A to mediate early exercise preconditioning.
Keywords：Protein kinase CExercise preconditioningmyocardialReperfusion injury
Publication Date：2019-03-02
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 69-75 )