Nicorandil improves myocardial high-energy phosphates in postinfarction porcine hearts.

摘要: 1. Nicorandil is a potent vasodilator combining the effects of nitrate with an ATP-sensitive potassium channel (K(ATP)) opener. Because postinfarct remodelled heart has increased vulnerability to subendocardial hypoperfusion, it possible that nicorandil could cause transmural redistribution blood flow away from subendocardium. Alternatively, K(ATP) opening exert beneficial effect on mitochondrial respiration. Consequently, present study was performed examine energy metabolism in heart. 2. Studies were swine which myocardial infarction produced by proximal left circumflex coronary artery ligation had resulted ventricular remodeling. [(31)P] nuclear magnetic resonance spectroscopy (MRS) used supply/demand relationship across wall while distribution examined radioactive microspheres. Data obtained during baseline conditions and infusion (100 microg, i.v., followed 25 microg/kg per min). 3. caused vasodilation preferential increase subepicardial flow; however, also significantly. no significant rate-pressure product or oxygen consumption. The ratio phosphocreatine (PCr)/ATP determined MRS abnormally depressed hearts (2.01 +/- 0.11, 1.85 0.10 1.59 0.11 for subepicardium, midwall subendocardium, respectively) compared normal (2.22 2.01 0.15 1.80 0.09, respectively). high-energy phosphate content hearts. However, PCr/ATP subendocardium 1.87 (P < 0.05). 4. Although modest ventricle, this associated towards normal. These results suggest exerts ventricle.