Effect of remifentanil on cell apoptosis during renal ischemia/reperfusion in rats

Objective To evaluate the effect of remifentanil on cell apoptosis during renal ischemia-reperfusion (I/R) in rats.Methods Seventy-five male Sprague-Dawley rats,weighing 220-250 g,were randomly divided into 3 groups (n =25 each):sham operation group (group S),I/R group,and remifentanil group (group R).Renal ischemia was induced by occlusion of the bilateral renal arteries for 45 min followed by reperfusion in groups I/R and R.Remifentanil was infused at 1.0 μg· kg-1 · min-1 via the caudal vein starting from 15 min before ischemia until 30 min of reperfusion in group R,while the equal volume of normal saline was given instead of remifentanil in groups S and I/R.At 15 min before ischemia (T0) and 3,6,12,24 h of reperfusion (T1-4),5rats were anesthetized and sacrificed,and renal specimens were obtained to detect the apoptotic rate and expression of Bax and Bcl-2 protein (by flow cytometry) and mRNA (by RT-PCR).The ratios between Bcl-2/Bax protein and mRNA expression were calculated.The pathological changes of renal tubules were scored.Results Compared with group S,the pathological scores and apoptotic rate were significantly increased at T1-4,and ratios between Bcl-2/Bax protein and mRNA expression were increased at T1,2,while decreased at T3,4 in groups R and I/R (P ＜0.01).Compared with group I/R,the pathological scores and apoptotic rate were significantly decreased at T1-4,while the ratios between Bcl-2/Bax protein and mRNA expression were increased in group R (P ＜ 0.05 or 0.01).Compared with the baseline value at T0,the pathological scores and apoptotic rates were significantly increased at T1 4,and the ratios of Bcl-2/Bax protein and mRNA expression were increased at T1,2,while decreased at T3,4 in groups R and I/R (P ＜ 0.01).Conclusion Regulation of Bcl-2/Bax expression and inhibition of cell apoptosis in renal tissues are involved in the mechanism by which remifentanil reduces renal I/R injury in rats. Key words: Piperidines ;  Apoptosis ;  Reperfusion injury ;  Kidney