门静脉高压症时细菌移位与内毒素血症和一氧化氮之间关系的实验研究

The relationship between bacterial translocation, endotoxemia and nitric oxide in portal hypertensive rats

目的 探讨门静脉高压症时细菌移位与内毒素血症和一氧化氮 (NO)之间的关系。方法 采用门静脉部分缩窄 (PVS)制成门静脉高压模型的 30只大鼠被均分为 3组 :模型组 (B)、左旋精氨酸组 (C)、单 甲基精氨酸组 (D)。另 10只大鼠接受假手术作为对照组 (A)。术后 2周取肠系膜淋巴结 (MLN)、脾和血标本进行细菌培养 ;测定门静脉压力、内毒素和NO2 -水平 ;并用镧做示踪剂观察肠粘膜屏障通透性变化和粘膜形态的改变。结果 PVS各组MLN细菌检出率均高于A组 ,血浆内毒素水平均上升。PVS各组NO2 -和门静脉压力均较A组增高 ,在D组二者均较B组下降。细菌移位率、内毒素和NO2 -水平之间呈显著正相关。镧沉积到PVS各组的粘膜上皮细胞和其下固有层细胞间 ,粘膜细胞的微绒毛有形态改变。结论 门静脉高压症可发生细菌移位和内毒素血症 ,可能与肠粘膜屏障通透性增强和破坏有关 ,提示细菌移位引起内毒素血症并增加NO2 -水平。

Objective To study the relationship between bacterial translocation,endotoxemia and nitric oxide(NO) in portal hypertensive rats.Method Portal hypertension was induced by portal vein stenosis(PVS) in 30 rats subdividing into 3 groups:group B (Model),group C in which L arginine was given,and group D receiving L NAME.10 additional normal rats served as control (group A).Two weeks after, mesenteric lymph nodes (MLN),spleen and blood samples were collected for bacterial cultures.Portal pressure,endotoxin and NO 2 - levels were measured.The permeability of intestinal mucosa was assayed using Lanthanum as tracer and the mucosa ultrastructure in ileum was observed.Results[WT5”BZ] The bacterial translocation rates in MLN in the PVS groups was higher than in control.The endotoxin levels elevated in the PVS group.NO 2 - level and portal pressure were lower in group D than in group B.In the PVS group,the tracer was observed in the lamina properia and epithelium layers.[WT5”HZ] Conclusions Bacterial translocation and endotoxemia in portal hypertension were in response to enhanced permeability of intestinal mucosa,which are responsible for the increased NO level.