Disruption of gut barrier function and cytokine responses after severe surgical stress-mechanism and treatment

观察生长激素(GH)和胰岛素样生长因子-I(IGF-I)对烧伤后肠源性脓毒症的治疗作用。BALB/c小鼠(n=50)皮下注射生长激素4.8 mg/kg/d、胰岛素样生长因子-I 24 mg/kg/d或安慰剂，每日2次，连续4天。然后给它们灌胃10^&lt；10&gt；大肠杆菌，并进行20%的全病火焰烧伤。所有小鼠在烧伤前5天接受异体输血，造成轻度免疫抑制。30只小鼠存活观察，20只小鼠于伤后20小时处死。GH和IGF-I治疗可减少烧伤后20小时移位至MLN和其他器官的发生率，并显著提高存活率。我们的结论是，GH和IGF-I在危重疾病中可能是有用的。实验I先前的研究表明，细菌易位与烧伤后的死亡率高度相关。进一步阐明细菌易位相关器官功能障碍和亚…的机制输血Balb/c小鼠口服200 mg/kg/d恩索前列素(PGEL类似物)或生理盐水3d后，灌胃10~14&gt；c；大肠杆菌，造成20%完全性火焰烧伤。根据我们先前的调查，这些小鼠的死亡率约为80%，而依索前列素使死亡率高达30%。伤后24小时处死动物，取肠系膜淋巴结(MLN)、肝、脾。通过放射性核素计数(DPM)和MLN和肝脏中的活菌落计数来确定细菌移位。测定肝组织髓过氧化物酶(MPO)活性，评价白细胞蓄积情况。与以前的工作一致，依索前列素显著减少了易位。与依索前列素组相比，对照组肝脏MPO显著增加。MPO与细菌移位程度显著相关(p&lt；0.05)。结果表明，细菌易位促进了中性粒细胞在肝脏的聚集，这可能是烧伤后脏器损伤的原因。实验二采用与实验二相同的模型，分离和培养脾巨噬细胞，分别加入和不加入10mcg/mlLPS，测定细胞培养上清液中肿瘤坏死因子、白介素1、白介素6和前列腺素E_2的含量。内毒素刺激巨噬细胞产生IL-1、IL-6和PGE2在恩索前列素治疗的动物中显著增加。伊尼索前列素治疗的动物体内先前缺乏巨噬细胞的最大刺激，当在体外进一步用脂多糖刺激时，可能会产生更多的细胞因子。较少

Experimenr IEffects of growth hormone (GH) and insulin-like growth factor I (IGF-I) administration on burn induced gut derived sepsis was evaluated. BALB/c mice (n=50) were treated subcutaneously with 4.8mg/kg/day of GH,24mg/kg/day of IGF-I or placebo twice a day for 4 days. Then they were gavaged with 10^<10>E.coli and subjected to 20% full sickness flame burn. All mice received allogeneic blood transfusion 5 days before burn to induce mild immunosuppression. Thirty mice were observed for survival and twenty mice were sacrificed at 20 hours post burn. GH and IGF-I administration reduced the incidence of translocation to MLN and other organs 20 hours post burn and significantly improved survival. We conclude that GH and IGF-I may be useful during critical illness.Experiment IIThe previous investigation revealed that bacterial translocation is highly associated with mortality after burn injury. To further clarify the mechanism of bacterial translocation related organ dysfunction and sub … More sequent death, we investigated the relation between the degree bacterial translocation and neutrophil accumulation in the liver.Blood transfused Balb/c mice were treated with oral 200mg/kg/day enisoprost (PGEl analog) or saline for three days and then they were gavaged with 10^<10 14>C E.coli and 20% full sickness flame burn was inflicted. According to our previous investigation, these mice have a mortality rate of approximately 80% and enisoprost improved the mortality to up to 30%. Animals were sacrificed 24 hour post burn and mesenteric lymph node (MLN), Liver, and spleen were harvested. Bacterial translocation were determined by both radionuclide count (dpm) and viable colony count in the MLN and Liver. Leukocyte accumulation was evaluated by the measurement of myeloperoxidase (MPO) in the liver. Consistent to previous work, enisoprost significantly reduced the translocation. MPO in the liver was significantly greater in the control group compared to enisoprost group. There was a significant correlation between MPO and the degree of bacterial translocation (p<0.05). It can concluded that bacterial translocation enhanced neutrophil accumulation in the liver which may be the cause of organ injury after burn injury.Experiment IIIUsing the same model as experiment II,splenic macrophages were separated and cultured for 24 hours with and without 10mcg/ml of LPS.TNF,IL-1 IL-6 and PGE2 in the cell culture supernatants were measured. LPS stimulated macrophage production of IL-1, IL-6 and PGE2 were significantly greater in enisoprost treated animals. It is likely that prior lack of in vivo maximal stimulation of macrophages in the enisoprost treated animals can produce greater amounts of cytokines when further stimulated with LPS in vitro. Less