【摘要】 目的研究TNF-α和TLR-4在呼吸机相关肺损伤大鼠肠道细菌移位中的作用。方法将24只SD大鼠随机分为3组,健康对照组(C组)、呼吸机相关肺损伤组(VILI组)、肠道抗生素组(AMP+VILI组),VILI组、AMP+VILI组以大潮气量机械通气制造大鼠呼吸机相关肺损伤模型,通气1 h后,改为小潮气量机械通气,AMP+VILI组在胃内灌入氨苄西林,3~4 h一次,共3次,造模后12 h,测大鼠回肠组织湿/干重比值,取肺脏、肝脏、胰腺、脾脏、肾脏、肠系膜淋巴结组织及回肠内容物行细菌培养及菌种鉴定,用real-time PCR检测回肠组织中TNF-αm RNA表达,ELISA测定回肠组织及0 min,30 min,1 h,2 h,4 h,6 h,8 h,12 h血清中TNF-α浓度,Western blot检测回肠黏膜组织中TLR-4的表达。结果 VILI组回肠组织TNF-αm RNA的表达较健康对照组上调(P<0.05),TNF-α、TLR-4浓度较C组升高(P均<0.05),细菌移位至肺及肠系膜淋巴结,其他器官未检测到移位的细菌;AMP+VILI组回肠组织中TNF-αm RNA的表达较VILI组下调(P<0.05),TNF-α、TLR-4浓度较VILI组降低,细菌移位减少(P均≥0.05)。结论呼吸机相关肺损伤中肠道细菌主要移位到损伤的肺,TNF-α、TLR-4浓度在呼吸机相关肺损伤大鼠肠道细菌移位中可能具有重要作用。抑制肠道细菌移位可能缓解呼吸机相关肺损伤。更多还原

【Abstract】 Objective To investigate the effect of tumor-necrosis-factor-alpha(TNF-α) and TOLL-like receptor4(TLR-4) on intestine bacteria translocation in ventilator-induced-lung-injury(VILI). Methods 24 SD mice were randomly divided into three groups: control group(spontaneously breathe), VILI group, and AMP(ampicillin) +VILI group. VILI group and AMP+VILI group were ventilated with high tidal volume for one hour, and then followed by low tidal volume for 12 hours. AMP+VILI group were administered intragastric ampicillin for 3 times, once per 3-4 hours after high tidal volume ventilation. All animals were sacrificed 12 h after modeling. The contents in mesenteric lymph nodes and distant sites(liver, spleen, pancreas, kidney, lung) were taken for bacterial culture and strain identification, the expression of TNF-α m RNA in ileal tissue was assayed by real-time PCR, TLR-4 by Western blot; The levels of TNF-α in ileum tissues and serum in different time points were determined by ELISA; the wet/dry ratio of ileum was measured. Results In group VILI, expression of TNF-α m RNA up-regulated, levels of TNF-α and TLR-4 in ileum tissues increased, and the bacteria counts in the mesenteric lymph nodes and lung increased significantly, compared with group control, no bacteria found in other distant sites, the level of TNF-α in serum increased in group VILI, compared to group control and reach peak at 6 hour. In group AMP+VILI, with all the above-mentioned abnormal changes alleviated significantly. Conclusion Levels of TNF-α, TLR-4 might play important roles in intestine bacterial translocation with the VILI model. Prohibiting bacteria translocation from intestine may mitigate VILI.更多还原