缺血预处理-后处理对大鼠肠缺血再灌注损伤的影响

Objective To evaluate the effects of ischemic preconditioning-postconditioning on the intestinal ischemia-reperfusion (IR) injury in rats. Methods Forty healthy male SD weighing 225-275 g were randomly assigned into 5 groups ( n = 8 each): group I sham operation (group S) ; group II intestinal IR (group IIR); group Ⅲ ischemic preconditioning (group Ipr); group IV ischemic postconditioning (group Ipo); group V Ipr+ Ipo. The rats were anesthetized with intraperitonel 20% urethane 5 ml/kg. Superior mesenteric artery (SMA) was occluded for 60 min followed by 60 min reperfusion. In group S, SMA was isolated but not occluded. In group Ipr, SMA was occluded for 10 min followed by 10 min reperfusion, and the rest procedures were performed using the method described in group IIR. In group Ipo, 60 min ischemia was followed by three 30 s episodes of ischemia at 30 s intervals for reperfusion. In group Ipr+ Ipo, Ipr was performed followed by Ipo and the procedures were performed using the methods described in group Ipr and Ipo. The animals were killed at 60 min of reperfusion. The intestinal tissues were immediately removed for determination of MDA content, SOD and MPO activities and the degree of damage to intestinal mucous membrane was scored according to Chiu score. Arterial blood samples were taken for determination of plasma concentrations of TNF-α and 1L-6. Results Compared with group S, Chiu score, MDA content, MPO activity, and plasma concentrations of TNF-α and IL-6 were significantly increased, whereas SOD activity decreased in the other 4 groups ( P < 0.05). Chiu score, MDA content, MPO activity, and plasma concentrations of TNF-α and IL-6 were significantly decreased, whereas SOD activity increased in group Ipr, Ipo and Ipr + Ipo as compared with group IIR ( P < 0.05). Chiu score and MDA content were significantly lower, whereas SOD activity higher in group Ipr + Ipo than in group Ipr and Ipo ( P < 0.05). No significant differences were detected in the indices between group Ipr and group Ipo ( P > 0.05). Conclusion Ischemic preconditioning-postconditioning can attenuate the intestinal IR injury in rats, and the efficacy is better than that of either Ipr or Ipo alone.

Effects of ischemic preconditioning-postconditioning on intestinal ischemia-reperfusion injury in rats