蜂胶水提液预处理对缺血再灌注大鼠小肠肠系膜微循环的改善作用及机制

Ameliorative effect of water extract of propolis preconditioning on mesenteric microcirculation of rats subjected to small intestinal ischemia reperfusion

目的:研究蜂胶水提液(WEP)预处理对缺血/再灌注(I/R)大鼠小肠肠系膜微循环的改善作用及其机制。方法:32只雄性Wistar大鼠随机分为假手术(sham)、I/R和WEP(100、200mg/kg)预处理组,以无创动脉夹夹闭肠系膜上动脉建立小肠I/R损伤模型,于再灌注2h时观测肠系膜微循环变化,分别采用Nackel氏分度法和测定小肠湿/干重比来判定肠道损伤水肿情况,酶联免疫吸附(ELISA)法测定血浆可溶性细胞间黏附分子-1(sICAM-1)含量,分光光度计法测定小肠组织髓过氧化酶(MPO)活性。结果:(1)与I/R组比较,WEP预处理组小肠病理变化明显减轻,Nackel氏分度和小肠湿/干重比明显降低(P<0.01);(2)WEP明显改善肠系膜微循环血流状态,减轻I/R所致的微动静脉收缩(P<0.05)、血流速度减慢(P<0.01)和微血管内白细胞贴壁滚动、黏附(P<0.01),且明显降低血浆sICAM-1含量(P<0.05)和小肠组织MPO活性(P<0.01)。结论:蜂胶水提液预处理可改善小肠I/R大鼠肠系膜微循环,其机制可能与抑制ICAM-1介导的中性粒细胞活化有关。

AIM ： To investigate the ameliorative effect of water extract of propolis （WEP） preconditioning on mesenteric microcirculation of rats subjected to small intestinal ischemia reperfusion （I/R）. METHODS： Thirty - two male Wistar rats were randomly divided into sham, I/R and WEP （100, 200 mg/kg） preconditioning groups. Model of small intestinal I/R injury was made by clamping super mesenteric artery for 45 min followed by 120 min of reperfusion in rats. Mesenteric microcirculation was detected at the end of reperfusion. The degree of small intestinal injury was assessed with Nackel＇s method and intestinal wet/dry ratio was determined. The content of soluble intercellular adhesion molecule - 1 （ sICAM - 1 ） in plasma and myeloperoxidase （MPO） activity in intestinal tissue were detected using enzyme linked - immuno - sorbent assay （ELISA） and spectrophotometer, respectively. RESULTS ： （ 1 ） WEP preconditioning alleviated significantly the pathologic lesion in small intestine, and resulted in a significant decreases in Nackel＇s score and intestinal wet/dry ratio, compared to those in I/R group （P 〈0. 01 ）. （2） The disturbance of the blood flow in microvessel induced by I/R was improved significantly by WEP. In addition, WEP preconditioning alleviated significantly the decrease in diam- eters of microvessels and microcirculatory blood velocity （P 〈 0. 05 vs I/R group） and inhibited the adherence of leukocytes to venute （P 〈0. 01 vs I/R group） in a dose -dependent manner. SICAM - 1 content in plasma and MPO activity in intestinal tissue were decreased in WEP preconditioning group, compared to those in I/R group （P 〈 0. 05 or P 〈 0. 01 ）. CONCLUSION： WEP preconditioning ameliorates mesenteric microcirculation of rats subjected to small intestinal I/R through suppressing the activation of polymorphonuclear neutrophils mediated by ICAM - 1.