Role of cannabinoid type 2 receptor in sevoflurane postconditioning-induced reduction of intestinal ischemia-reperfusion injury in rats / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the role of cannabinoid type 2 receptor (CB2R) in sevoflurane postconditioning-induced reduction of intestinal ischemia-reperfusion (I/R) injury in rats.Methods:Twenty-four clean-grade healthy male Sprague-Dawley rats, aged 8-10 weeks, weighing 220-270 g, were divided into 4 groups ( n=6 each) using a random number table method: sham operation group (group Sham), intestinal I/R group (group I/R), intestinal I/R+ sevoflurane postconditioning group (group Sevo) and intestinal I/R+ sevoflurane postconditioning+ CB2R antagonist AM630 group (group AM). The model of intestinal I/R injury was established by occluding the superior mesenteric artery for 45 min followed by 2 h reperfusion.In the group Sevo, 2% sevoflurane was inhaled immediately at the beginning of reperfusion for 30 min.In the group AM, CB2R antagonist AM630 3 mg/kg was intraperitoneally injected at 1 h before ischemia, and the other treatments were similar to those previously described in group Sevo.At 2 h of reperfusion, the animals were sacrificed after anesthesia, and small intestinal tissues were obtained for microscopic examination of the pathologic changes which was scored according to Chiu and for determination of wet/dry weight ratio (W/D ratio), for detection of malondialdehyde (MDA) content (by thiobarbituric acid colorimetry), for determination of myeloperoxidase (MPO) activity (by MPO assay) and cleaved caspase-3 protein expression (by Western blot). Results:Compared with group Sham, the Chui score, W/D ratio, MDA content and MPO activity in the intestinal tissues were significantly increased, cleaved caspase-3 expression was up-regulated in group I/R ( P<0.05). Compared with group I/R, the Chui score, W/D ratio, MDA content and MPO activity in the intestinal tissues were significantly decreased, cleaved caspase-3 expression was down-regulated in group Sevo ( P<0.05). Compared with group Sevo, the Chui score, W/D ratio, MDA content and MPO activity were significantly increased, cleaved caspase-3 expression was up-regulated in group AM ( P<0.05). Conclusion:CB2R is involved in the process of sevoflurane postconditioning-induced reduction of intestinal I/R injury in rats.