舒芬太尼预处理对肠缺血再灌注大鼠急性肺损伤的影响及阿片受体在其中的作用

Effect of sufentanil preconditioning on acute lung injury induced by intestinal ischemia-reperfusion in rats and the role of opioid receptors

目的评价舒芬太尼预处理对肠缺血再灌注大鼠急性肺损伤的影响及阿片受体在其中的作用。方法成年健康雄性Wistar大鼠48只，体重200．250g，采用随机数字表法，将其随机分为6组（n=8）：假手术组（s组）、肠缺血再灌注组（I／R组）、舒芬太尼预处理组（SPC组）、COTP＋SPC组、NTD＋SPC组和nor-BNI＋SPC组。I／R组、SPC组、COTP＋SPC组、NTD＋SPC组和nor-BNI＋SPC组采用夹闭肠系膜上动脉45min，再灌注2h的方法制备肠缺血再灌注模型；s组仅分离肠系膜上动脉，不夹闭。SPC组、COTP＋SPC组、NTD＋SPC组和nor-BNI＋SPC组于缺血前10min时静脉注射舒芬太尼10μg／kg；COTP＋SPC组、NTD＋SPC组于注射舒芬太尼前10min时分别静脉注射“受体拮抗剂COTP1mg／kg或8受体拮抗剂NTD5mg／kg；nor-BNI＋SPC组于注射舒芬太尼前15min时静脉注射Jc受体拮抗剂nor-BNI5mg／kg。于再灌注2h时处死大鼠，取肠组织，观察肠粘膜形态并进行肠粘膜损伤评分；取左肺组织，观察肺组织形态并进行肺损伤评分；采用TUNEL法检测肺组织细胞凋亡情况，计算凋亡指数；采用免疫组化法测定肺组织Bcl-2蛋白和Bax蛋白的表达，计算Bcl-2／Bax比值。结果与s组比较，I／R组、SPC组、COTP＋SPC组、NTD＋SPC组和nor-BNI＋SPC组肠粘膜损伤评分、肺损伤评分和凋亡指数升高，Bcl-2蛋白和Bax蛋白表达上调，Bcl-2／Bax比值降低（P〈0．01）；与I／R组比较，SPC组肠粘膜损伤评分、肺损伤评分和凋亡指数降低，Bcl-2蛋白表达上调，Bax蛋白表达下调，Bcl-2／Bax比值升高（P〈0．01）；与SPC组比较，COTP＋SPC组、NTD＋SPC组和nor-BNI＋SPC组肠粘膜损伤评分、肺损伤评分和凋亡指数升高，Bcl-2蛋白表达下调，Bax表达蛋白表达上调，Bcl-2／Bax比值下降（P〈0．01）。结论舒芬太尼预处理可减轻肠缺血再灌注大鼠急性肺损伤，该作用与激活阿片受体有关。

Objective To evaluate the effect of sufentanil preconditioning on acute lung injury induced by intestinal ischemia-reperfusion （I/R） in rats and the role of opioid receptors. Methods Forty-eight male Wistar rats weighing 200-250 g were randomly divided into 6 groups （ n = 8 each） ： sham operation group （group S） ; I/R group; sufentanil preconditioning group （group SPC）; COTP （μ receptor antagonist） ＋ SPC group; NTD （8 receptor antagonist） ＋ SPC group and nor-BNI （to receptor antagonist） ＋ SPC group. Intestinal I/R was produc.ed by occlusion of the superior mesenteric artery for 45 min followed by 2 h reperfusion in groups I/R, SPC, COTP ＋ SPC, NTD ＋ SPC and nor-BNI ＋ SPC. Sufentanil 10μg/kg was injected intravenously at 10 min before ischemia in groups SPC, COTP ＋ SPC, NTD ＋ SF＇C and nor-BNI ＋ SPC. COTP 1 mg/kg and NTD 5 mg/kg were injected intravenously at 10 min before sufentanil injection in groups COTP ＋ SPC and NTD ＋ SPC respectively, while nor-BNI 5 mg/kg was injected intravenously at 15 min before sufentanil administration in group nor-BNI ＋ SPC. The animals were sacrificed at 2 h of reperfusion, the intestinal tissue was removed for microscopic examination and intestinal damage was assessed and scored according to Chiu. Left lung tissue was also removed for microscopic examination （1 = normal, 4 = severely injured）. The apoptosis in lung cells was detected using TUNEL and apoptosis index （AI） was calculated. The expression of Bcl-2 and Bax proteins in lung tissues was detected using immuno-histochemistry and Bcl-2/Bax ratio was calculated. Results Compared with group S, Chiu＇s score, lung injury score and AI were significantly increased, expression of Bcl-2 and Bax proteins was up-regulated, Bcl-2/Bax ratio was significantly decreased in the other groups （P 〈 0.01 ）. Compared with group I/R, Chiu＇ s score, lung injury score and AI were significantly decreased, Bcl-2 protein expression was up-regulated, Bax protein expression was down- regulated, and Bcl-2/Bax ratio was significantly increased in group SPC （ P 〈 0.01 ）. Compared with group SPC, Chiu＇s score, lung injury score and AI were significantly increased, Bcl-2 protein expression was down-regulated, Ban protein expression was up-regulated, and Bcl-2/Bax ratio was siguificantly decreased in groups COTP ＋ SPC, NTD ＋ SPC and nor-BNI ＋ SPC （ P 〈 0.01 ）. Conclusion Sufentanil preconditioning can attenuate lung injury in- duced by intestinal I/R by activation of opioid receptors in rats.