Experimental study on the mechanism of K_(ATP) channel in ischemic preconditioning

Objective This study was designed to elucidate whether the myocardial protective effects conferred by ischemic preconditioning (IP) or adenosine which was associated with opening of ATP sensitive potassium channels (K ATP channel ). Methods Thirty six isolated buffer perfused rabbit hearts underwent 30 minutes of normothermic potassium arrest followed by 1 hour reperfusion.They were divided into 6 groups: group 1, served as control; group 2, ischemic preconditioning; group 3, treated with adenosine(20 μmol/L); group 4, IP + glibenclamide (10 μmol/L); group 5, adenosine (20 μmol/L)+glibenclamide (10 μmol/L); group 6, control+glibenclamide(10 μmol/L). Results I.P. or adenosine significantly improved the cardiac function and reduced the leakage of myocardial enzymes as compared with that of the control group. Conclusion The beneficial effects of both IP and adenosine were strengthened by K ATP channels which play an important role in the protective effects of IP and adenosine on the myocardium.