Protective effects of ATP-sensitive potassium channel opener on ischemia/reperfusion injury in isolated rabbit hearts

Objective To investigate the protective effects of pinacidil, an ATP-sensitive potassium channel opener, on ischemia/reperfusion injury of myocardium in isolated rabbit hearts. Methods Observation was made on rabbit hearts perfused with Langendorff apparatus. 16 rabbits were randomly divided into control group and pinacidil group with 40 minute occlusion followed by 20 minute reperfusion after cardiac arrest with cold cardioplegia. Pinacidil 10μmol/L was infused 15 minutes before cardioplegic heart arrest in pinacidil group Morphological structure,hemodynamics variables,myocardial levels of adenine nucleotides and lipid peroxide were measured. Results (1) In pinacidil group, the recovery of myocardial contractility and heart rate were improved. (2) Pinacidil group had much higher levels of myocardial adenosine triphosphate (ATP),energy charge (EC) and total adenine nucleotide (TAN) than control group had (P0.05 or 0. 01). (3) Myocardial MDA level of pinacidil group was obviously lower than that of control gourp. Conclusion Pinacidil may enhance myocardial protection against ischemia/reperfusion injury.