Effect of remifentanil preconditioning on myocardial ischemia-reperfusion injury in aged rats

Objective To evaluate the effect of remifentanil preconditioning on myocardial ischemia-reperfusion (I/R) injury in aged rats. Methods Twenty-four healthy male Sprague-Dawley rats, aged 15-18 months, weighing 465-580 g, were randomly divided into 3 groups (n = 8 each) using a random number table: sham operation group (group S), group I/R and remifentanil preconditioning group (group RP). The animals were anesthetized with intraperitoneal 10% chloral hydrate 300 mg/kg.Myocardial I/R was induced by 30 min occlusion of anterior descending branch of left coronary artery followed by 120 min reperfusion in group I/R.In group RP, remifentanil 10 μg · kg-1· min-1 was infused intravenously for 20 min followed by 10 min washout before myocardial I/R.In group S, the anterior descending branch was only exposed but not ligated.At 30 min before ligation and 120 min of reperfusion, the activities of serum lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) were determined.The hearts were removed at 120 min of reperfusion for determination of myocardial infarct size, the percentage of myocardial infarct size was calculated, and myocardial specimens were obtained for observing myocardial ultrastructure. Results Compared with group S, the activities of serum LDH and CK-MB were significantly increased at 120 min of reperfusion in I/R and RP groups.Compared with group I/R, the activities of serum LDH and CK-MB were significantly decreased, the percentage of myocardial infarct size was decreased, and the pathological changes were attenuated in group RP. Conclusion Remifentanil preconditioning can attenuate myocardial I/R injury in aged rats. Key words: Piperidines; Ischemic preconditioning; Myocardial reperfusion injury; Aged