静脉注射内毒素法制作大鼠肠道细菌易位模型

A model of bacterial translocation from intestine in rats induced by endotoxin injection intravenously

目的探讨静脉注射内毒素制作大鼠肠道细菌易位模型的方法。方法60只雄性SD大鼠(体重200～250g)随机分为4组(15只/组)。其中3组为实验组,按组别不同分别给予尾静脉注射内毒素2、4、6mg/kg;对照组给予尾静脉注射生理盐水0.5ml。观察各组大鼠的体温、呼吸频率、外周血白细胞计数及死亡率,7d后将各组大鼠分别开腹取门静脉血、下腔静脉血、肠系膜淋巴结、肝、脾和胰腺组织作细菌培养。结果注射内毒素后各组大鼠的体温、呼吸频率及外周血白细胞均有不同程度的升高。2mg/kg组大鼠无死亡,组织细菌培养阳性率为24.4%。4mg/kg组的死亡率为20.0%,细菌培养阳性率为47.2%,其中肠系膜淋巴结阳性率为83.3%。6mg/kg组的死亡率为46.7%,细菌培养阳性率为64.6%,其中肠系膜淋巴结阳性率为100.0%。结论4mg/kg剂量的内毒素静脉注射是制作大鼠肠道细菌易位模型的较为理想可行的方法。

Objective To explore a model of bacterial translocation from intestine in rats induced by endotoxin injection intravenously. Methods Sixty male Sprague-Dawley rats(weighted by 200～250 g) were randomly divided into 4 groups (15 rats/group). The control group received an intravenous injection of 0.5 ml saline solution. Three experimental groups received 2 mg/kg, 4 mg/kg and 6 mg/kg endotoxin intravenous injection respectively. The temperature(T), respiration(R), white blood cell count (WBC) and mortality in each group were observed. 7 days later, all survival rats were dissected and bacterial culture from mesenteric lymph nodes, liver, spleen, pancreas, blood from portal vein and inferior vena cava were performed. Results T, R and WBC elevated in all the 3 experimental groups after injection. No rat died in 2 mg/kg group, and the positive ratio of bacterial culture was 24.4%. In 4 mg/kg group, the mortality was 20.0%and the positive ratio of bacterial culture was 47.2%(83.3%in mesenteric lymph nodes particularly). In 6 mg/kg group, the mortality was 46.7%and the positive ratio of bacterial culture was 64.6%(100.0%in mesenteric lymph nodes particularly). Conclusion Intravenous injection of 4 mg/kg endotoxin is a satisfied method for the model of bacterial translocation from intestine in rats.