Effects of remifentanil pretreatment on myocardial ischemia-reperfusion injury in rabbits

Objective To investigate the effects of remffentanil pretreatment on myocardial ischemiareperfusion (I/R) injury in rabbits. Methods Thirty healthy rabbits, aged 12-18 months, weighing 2.5-3.5 kg,were randomly divided into 3 groups (n = 10 each): I/R group, low-dose remifentanil pretreatment group (group R1 ) and high-dose remifentanil pretreatment group (group R2 ). Myocardial I/R was induced by ligation of anterior descending branch of left coronary artery for 30 min followed by 6 h of reperfusion in the 3 groups. Remifentanil was infused intavenously at 1.65 and 3.30 μg· kg - 1 · min- 1 for 30 min before ischemia in group R1 and R2 respectively, while equal volume of normal saline was infused instead in group I/R. Blood samples were taken for determination of serum cardiac troponin-Ⅰ (cTnI) and creatine kinase-MB isoenzyme (CK-MB) concentrations before administration (baseline), after administration, at 30 min of ischemia and at 6 h of reperfusion. The rabbits were then sacrificed and hearts removed. Myocardial tissues were obtained for microscopic examination. Results Serum cTnI and CK-MB concentrations were significantly lower in group R1 and R2 than in group I/R and serum cTnI concentration lower in group R2 than in group R1 ( P ＜ 0.01). Remifentanil infusion significantly attenuated the pathologic changes in a dose-dependent manner. Conclusion Remifentanil pretreatment provides protective effect against myocardial I/R injury in rabbits and it is related to the dose. Key words: Piperidines; Myocardial reperfusion injury