肠淋巴途径在失血性休克大鼠肠源性细菌/内毒素移位发病学中的作用

目的观察失血性休克大鼠肠系膜淋巴液及门静脉血毒性物质的变化，同时观察结扎肠系膜淋巴管对重症失血性休克大鼠器官内毒素（ET）及肠系膜淋巴结和脾脏组织细菌培养的影响，探讨肠淋巴途径在休克大鼠肠源性细菌／内毒素移位（BET）发病学中的作用。方法雄性Wistar大鼠24只被随机分为休克组及对照组。复制重症失血性休克大鼠模型后，分别留取休克淋巴液、休克门静脉血、正常淋巴液、正常门静脉血，检测其中的ET、肿瘤坏死因子-α（TNF～α）、白细胞介素-6（IL-6）水平。另取30只大鼠被随机分为假手术组、休克组、结扎组。休克组与结扎组复制重症失血性休克大鼠模型。结扎组于休克复苏后行肠系膜淋巴管结扎术，分别于休克输液复苏3h和6h后，制备肺、肝、心、肾组织匀浆，检测其中ET含量；制备肠系膜淋巴结和脾组织匀浆，进行细菌培养。结果休克淋巴液中ET、TNF—α、IL-6的含量均显著高手休克血浆、正常血浆和正常淋巴液（P均〈0．01）；失血性休克大鼠输液复苏后3h和6h肺、肝、心、肾组织中ET含量均显著高于假手术组与结扎组（P〈0．05或P〈0．01）；休克组大鼠复苏后3h和6h肠系膜淋巴结及脾组织中均可见细菌生长，而结扎组大鼠相应组织中则无细菌生长。结论肠淋巴途径在失血性休克致大鼠肠道屏障功能下降、引起肠源性BET的发病学中具有首要作用。

Role of intestinal lymphatic pathway in pathogenesis of intestine-derived bacteria/endotoxin translocation in rats in shock

OBJECTIVE: To observe the changes of toxic substances in mesenteric lymph and portal vein blood of rats in hemorrhagic shock, and the influence of mesenteric lymph duct ligation on level of endotoxin (ET) in organs and bacterial contents in mesenteric lymph nodes (MLN) and spleen in rats with hemorrhagic shock, and to evaluate the role of lymphatic pathway in pathogenesis of intestine-derived bacteria/endotoxin translocation (BET) in rats with shock. METHODS: Twenty-four male Wistar rats were randomly divided into the shock group and control group. A model of serious hemorrhagic shock was reproduced by blood shedding to maintain the blood pressure at 40 mm Hg (1 mm Hg=0.133 kPa) for 90 minutes under aseptic condition, and MLN and portal vein blood were harvested. The specimens were also obtained in control group. The contents of ET, tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were determined in them. Thirty male Wistar rats were randomly divided into the sham operation group, shock group and lymphatic duct ligation group. Mesenteric lymph ducts were ligated after resuscitation. All rats were sacrificed, and lung, liver, heart and kidney were removed and homogenized for determination of the content of ET. MLN and spleen homogenates were subjected to bacterial culture. RESULTS: The contents of ET, TNF-alpha and IL-6 in lymph were significantly higher than those of plasma in shock group, and also higher than that in normal plasma and normal lymph (all P<0.01). In shock group the contents of ET in lung, liver, heart and renal homogenate 3 and 6 hours after transfusion and resuscitation were significantly higher than those of sham operation group and ligation group (P<0.05 or P<0.01). Bacterial culture of MLN and spleen in shock group rats 3 and 6 hours after transfusion and resuscitation was positive, but it was not in ligation group. CONCLUSION: The results demonstrate that the intestinal lymphatic pathway plays an important role after compromise of gut barrier function in carrying out BET after hemorrhagic shock.