丙酮酸对大鼠移植小肠黏膜组织超氧化物歧化酶活力的影响

Effects of pyruvate on the activity of superoxide dismutase in transplanted small intestine of rats

目的丙酮酸对大鼠移植小肠缺血再灌注损伤具有保护作用,本研究旨在探索影响移植小肠黏膜组织中超氧化物歧化酶(SOD)活力是否为其作用途径之一。方法选用近交系成年雄性SD大鼠,按随机数字表法分为3组:假手术组,行剖腹、左侧肾切除术;建立小肠移植缺血再灌注动物模型,分为移植组和丙酮酸处理组,后者分别于供体小肠阻断血流、灌洗前10 min向肠腔内注入10 ml含0.26 g多聚葡萄糖的营养液和含0.32 g分析纯丙酮酸的营养液。分别留取缺血45、90 min和再灌注30、180 min小肠组织标本,观察小肠组织损伤病理变化并进行Chiu’s评分,采用黄嘌呤氧化酶法测定小肠组织中的SOD活力。结果①缺血再灌注不同时相移植组小肠组织损伤程度均重于其他两组(P<0.01),而丙酮酸处理组小肠组织损伤程度与假手术组差异无统计学意义。②小肠黏膜组织匀浆中SOD活力随着缺血以及再灌注时间的延长而逐渐降低,再灌注30 min时SOD活力下降迅速,至再灌注180 min时回升,但仍未恢复至正常水平。移植组各时间点与假手术组及丙酮酸处理组比较均明显降低(P<0.01)。丙酮酸处理组小肠组织中SOD活力与假手术组比较变化不明显。结论丙酮酸对大鼠移植小肠缺血再灌注损伤具有保护作用,可能是通过保护和恢复大鼠移植小肠组织中SOD的活力,进而减轻氧自由基损伤的途径起作用。

Objective Pyruvate has a protective effect on ischemia-reperfusion injury of transplanted small intestine in rats.The purpose of this study is to determine whether the activity of superoxide dismutase(SOD)in transplanted small intestine is one of the pathways.Methods Adult male Sprague-Dawley rats of inbred line were selected and divided into 3 groups according to random number table method,and sham operation group underwent laparotomy and left nephrectomy.Intestinal transplantation ischemia-reperfusion animal models were established,which were divided into transplantation group and pyruvate pretreatment group.The latter group was injected 10 ml full-power and pure pyruvate nutrient solution into the intestinal cavity 10 min before the donor intestinal blocking blood flow and lavage,respectively.Small intestinal tissue samples were collected at 45,90 min after ischemia and 30,180 min after reperfusion,respectively.The pathological changes of small intestinal tissue damages were observed under a light microscope,and the activity of SOD in small intestinal tissue was determined by xanthine oxidase method.Results(1)The degree of small intestinal tissue injury in the transplantation group was higher than that in the other two groups(P<0.01),but there was no significant difference between the pyruvate pretreatment group and the sham operation group.(2)The activity of SOD in the homogenate of small intestinal mucosal tissues decreased gradually with the prolongation of ischemia and reperfusion time.The activity of SOD decreased rapidly after 30 min of reperfusion,and recovered at 180 min of reperfusion,but still did not return to the normal level.Compared with sham operation group and pyruvate pretreatment group,the transplantation group was significantly reduced at each time point(P<0.01).The activity of SOD in the small intestine of pyruvate pretreatment group was not significantly changed compared with the sham operation group.Conclusion Pyruvate has a protective effect on ischemia-reperfusion injury of transplanted small intestine in rats,which may play a role by protecting and restoring the activity of SOD in transplanted small intestine of rats,thereby reducing the damage caused by oxygen free radicals.