Research on Changes of the Pore-Forming Subunit kir6.2 of Myocardial Sarcolemmal ATP-Sensitive Potassium Channels in Myocardial Protection of Exercise Preconditioning

Objective:To study the changes of the Pore-Forming Subunit kir6.2 of myocardial sarcolemmal ATP-sensitive potassium (SarcKATP) channels in myocardial protection of exercise preconditioning (EP) and the relations with protein kianse C (PKC) .Methods:SD rats were divided into control group (C) , EE group, EP group, EP+EE group, CHE+EP group and CHE+EP+EE group.By using once heavy intensity interval treadmill running, this paper establishes EP model, and exhaustive exercise on treadmill to induce rats myocardial injury.In-situ hybridization and real-time fluorescence quantitative PCR methods were used to detect changes of kir6.2 mRNA.Immunofluorescence and westten blotting methods were used to detect changes of kir6.2 protein.Results:Compared with group C, there is no significant change of kir6.2 mRNA in group EE and EP, while kir6.2 protein significantly increased in group EE and significantly decreased in group EP.Compared with group EE, no significant changes of kir6.2 mRNA in group EP+EE, kir6.2 protein in group EP+EE significantly decreased.Compared with group EP, kir6.2 mRNA significantly decreased in group CHE+EP, kir6.2 protein significantly increased in group CHE+EP.Compared with group EP+EE, there is no significant changes of kir6.2 mRNA and kir6.2 protein in group CHE+EP+EE.Conclusion:In myocardial protection induced by EP, kir6.2 mRNA did not changed significantly, while kir6.2 protein decreased significantly, which demonstrated myocardial SarcKATP channels mediated myocardial protection induced by EP through kir6.2 protein decreased.PKC can regulate expression of myocardial SarcKATP channels.