大黄对肠缺血再灌注大鼠肠黏膜和通透性的影响及其机制

目的：观察肠缺血再灌注损伤后,肠内补充大黄对大鼠肠黏膜结构和通透性的影响,并探讨其作用机制。方法：雄性SD大鼠30只,随机分为3组（n=10）。大黄组：夹闭肠系膜上动脉建立肠缺血再灌注损伤模型,肠外营养＋肠内大黄液;模型组：建立肠缺血再灌注损伤模型,肠外营养;对照组：分离肠系膜上动脉但不夹闭,自由饮食。术后第3天收集尿液,采用双糖法（乳果糖/甘露醇）反应肠黏膜通透性,第6天处死大鼠留取小肠检测黏膜结构和热休克蛋白70（HSP70）含量。结果：对照组和大黄组肠黏膜通透性均低于模型组（P〈0.01）。大黄组肠黏膜通透性虽高于对照组,但无统计学意义（P〉0.05）;模型组小肠绒毛高度、黏膜厚度显著低于对照组和大黄组（P〈0.01）,大黄组接近于对照组（P〉0.05）;小肠全层厚度各组间无统计学差异;对照组和大黄组HSP70含量均高于模型组（P〈0.01）。大黄组HSP70含量虽略高于对照组,但差异无统计学意义（P〉0.05）。结论：大黄可减少肠缺血再灌注损伤引起的肠黏膜通透性增加,保护肠黏膜结构。大黄的肠道保护作用与多种机制有关,诱导小肠HSP70表达增加可能是其中之一。

Effects of rhubarb on enteric mucosa structure and permeability in intestinal ischemia reperfusion rats and its mechanisms

AIM： To observe the protective effect of rhubarb on enteric mucosa structu and permeability of rats intestine after ischemia reperfusion, and its possible mechanisms. METHODS： 30 male SD rots were divided into Rhubarb, Model and Control Groups randomly（ n = 10）. The model rats were established by blocking superior mesenteric artery （SMA）, and total parenteral alimentation （TPN） was done. Rhubarb and the same voluIne of normal saline were given orally in Rhubarb and Model groups respectively. SMA was decoherenced but not blocked in Control Group. The 24 h urine was collected at day 3 after the operation and the enteric mucosa pe~ility was determined by disac- charide assay. The 10 cm jejunum and 10 cm ileum were collected at day 6 for mucosa structure and HSP70 study. RESULTS： The enteric mucosa permeability of Control and Rhubarb group were lower than that in Molel Group （P 〈 0.01 ）, though that in Rhubarb Group was higher than that in Control Group, there was no statistical difference （P 〉 0.05）. The villi height and mucesa thickness of small intestine in Model Group were significantly lower than those of Control and Rhu- barb Group（ P 〈 0.01）. Those of Rhubarb Group were similar to those of Control Group （ P 〉 0.05）. There was no statistics difference between three groups in full thickness of small intestine. The content of HSP70 in Model Group was much lower than those in Control and Rhubarb Groups（ P 〈 0.01 ）. The content of HSP70 in Rhubarb group was higher than that in Control Group, but there was no statistics difference （ P 〉 0.05 ）. CONCLUSION： Administration of rhubarb orally can decrease the enteric mucosa structure and permeability change after I/R injury. Rhubarb protects the gut maybe by inducing more expressed HSP70 in the intestine.