腹内高压对兔肠道通透性及内毒素细菌移位的影响

Influence of intra-abdominal hypertension on the intestinal permeability and endotoxin/bacteria translocation in rabbits

目的 观察不同程度腹内压及作用时间对兔肠粘膜通透性及内毒素、细菌移位的影响 ,探讨腹内高压 (IAH)在腹腔间隙综合征形成及多器官功能障碍中的作用。 方法 制作IAH动物模型 ,通过异硫氢酸荧光素葡聚糖 (FITC Dextran )和辣根过氧化酶Ⅱ型 (HRP Ⅱ )两种分子探针 ,观察不同程度腹内压力下肠道通透性的改变 ,检测IAH对肠道细菌、内毒素移位的影响。 结果 腹内压 (IAP) >2 0mmHg(1mmHg =0 .133kPa)时 ,门静脉血中FITC D及HRP Ⅱ含量显著增高 (P<0 .0 1) ;IAP为 10mmHg作用 1、2、4h ,门静脉血中内毒素含量与正常对照组相比无显著改变 ;2 0mmHg压力作用 1h ,内毒素含量即显著增高 ,并随压力增高及作用时间的延长呈上升趋势。细菌培养结果显示 ,2 0mmHg压力下 1、2、4h ,细菌到肠系膜淋巴结的移位率分别为 33.3%、6 6 .7%、10 0 % ,2、4h各有 1例移位到肝脏 ;30mmHg时 2h以内 ,细菌到肠系膜淋巴结的移位率为 10 0 %。所有实验组均未出现细菌至脾脏的移位。 结论 当IAP >2 0mmHg时肠道通透性显著增加 ,门静脉血内毒素含量显著升高 ,细菌可移位至肠系膜淋巴结及肝脏 ,可能是导致腹腔间隙综合征及多器官功能障碍综合征 (MODS)的重要原因之一。

Objective To observe different degrees of intra abdominal pressure and different duration on the intestinal permeability and endotoxin/bacteria translocation in rabbit model, so as to explore the mechanism of the development of abdominal compartment syndrome (ACS) and MODS. Methods Rabbit model of intra abdominal hypertension was established by injection of gaseous nitrogen into the peritoneal cavity. Thirty nine New Zealand white rabbits were employed in the study. The change in intestinal permeability was determined by fluorescein isothiocyanate dextran(FITC D) and two kinds of molecular probes of type Ⅱ horseradish peroxidase (HRP Ⅱ). The effects of intra-abdominal hypertension on the endotoxin/bacteria translocation were also detected. Results The contents of FITC D and HRP Ⅱ in portal veins increased evidently (P<0.01) when intra-abdominal pressure (IAP) was higher than 20 mmHg. The endotoxin (ET) content in portal vein in rabbits with IAP of 10 mmHg for 1, 2 and 4 hours exhibited no difference compared with that in normal control,while the ET content increased obviously after 1 hour with IAP of 20 mmHg and increased thereafter along with the prolongation of IAP,and increase in pressure.The bacterial translocation rates were 33.3%,66.7% and 100% when IAP was maintained at 20 mmHg for 1, 2 and 4 hours, respectively,and there was evidence of bacterial translocation to the liver. The rate of bacterial translocation to intestinal mesenteric lymph nodes was 100% when IAP was 30 mmHg for 1 and 2 hours. There was no bacterial translocation to the spleen in all experimental rabbits. Conclusion Intestinal mucosal permeability increased significantly with increased endotoxin content in portal vein when IAP was higher than 20 mmHg. At the sane time, the bacteria could be translocate to intestinal mesenteric lymph nodes and liver, which might be constitute one of the important factors leading to the development of ACS and MODS. [