AIM:To study whether over-starvation aggravates intestinal mucosal injury and promotes bacterial and endotoxin translocation in a high-altitude hypoxic environment.METHODS:Sprague-Dawley rats were exposed to hy-pobari...AIM:To study whether over-starvation aggravates intestinal mucosal injury and promotes bacterial and endotoxin translocation in a high-altitude hypoxic environment.METHODS:Sprague-Dawley rats were exposed to hy-pobaric hypoxia at a simulated altitude of 7000 m for 72 h.Lanthanum nitrate was used as a tracer to detect intestinal injury.Epithelial apoptosis was observed with terminal deoxynucleotidyl transferase dUTP nick end labeling staining.Serum levels of diamino oxidase(DAO),malondialdehyde(MDA),glutamine(Gln),superoxide dismutase(SOD) and endotoxin were measured in intestinal mucosa.Bacterial translocation was detected in blood culture and intestinal homogenates.In addition,rats were given Gln intragastrically to observe its protective effect on intestinal injury.RESULTS:Apoptotic epithelial cells,exfoliated villi and inflammatory cells in intestine were increased with edema in the lamina propria accompanying effusion of red blood cells.Lanthanum particles were found in the intercellular space and intracellular compartment.Bacterial translocation to mesenteric lymph nodes(MLN) and spleen was evident.The serum endotoxin,DAO and MDA levels were significantly higher while the serum SOD,DAO and Gln levels were lower in intestine(P< 0.05).The bacterial translocation number was lower in the high altitude hypoxic group than in the high altitude starvation group(0.47±0.83 vs 2.38±1.45,P<0.05).The bacterial translocation was found in each organ,especially in MLN and spleen but not in peripheral blood.The bacterial and endotoxin translocations were both markedly improved in rats after treatment with Gln.CONCLUSION:High-altitude hypoxia and starvation cause severe intestinal mucosal injury and increase bacterial and endotoxin translocation,which can be treated with Gln.展开更多
目的:探讨SD大鼠在急性低氧肺损伤形成过程中N A L P 3炎性体的表达变化及其意义。方法:将40只SD大鼠随机分为4组:正常对照组、模拟海拔5 000 m 1 d组、3 d组、7 d组。分别在进入模拟海拔5 000 m后1、3、7 d取肺组织。血气分析仪检测动...目的:探讨SD大鼠在急性低氧肺损伤形成过程中N A L P 3炎性体的表达变化及其意义。方法:将40只SD大鼠随机分为4组:正常对照组、模拟海拔5 000 m 1 d组、3 d组、7 d组。分别在进入模拟海拔5 000 m后1、3、7 d取肺组织。血气分析仪检测动脉血气;电子天平称量肺组织湿干重并计算湿/干比值;显微镜下观察肺组织形态结构变化和超微结构变化;免疫组化法检测肺组织NALP3、caspase-1、IL-1β蛋白表达水平;ELISA法检测血清IL-1β水平。结果:肺组织病理炎症评分的等级实验各组均高于对照组(P<0.05),3 d组高于1 d、7 d组(P<0.05);电镜结果显示:实验组肺泡II型上皮细胞内有空泡,肺泡腔内较多巨噬细胞;免疫组化结果显示:NALP3、caspase-1、I L-1β的表达1 d开始增加,3 d达到高峰,7 d下降(P<0.0 5),与肺损伤程度呈正相关(r=0.8 1,P=0.01;r=0.76,P=0.03;r=0.84,P=0.01)。实验各组血清IL-1β水平高于对照组(P<0.05),3 d组高于1 d、7 d组(P<0.05)。结论:低氧急性肺损伤早期,NALP3炎性体被激活,通过caspase-1的活化,下游信号IL-1β成熟释放增加,引发肺损伤,提示NALP3炎性体可能在高原低氧急性肺损伤的发生发展中发挥作用。展开更多
基金Supported by Scientific and Technical Research Funds from Chinese PLA during the Eleventh Five-Year Plan Period,No. 2008G093National Natural Science Foundation of China,No. 30900715National Science and Technology Ministry,No. 2009BAI85B03
文摘AIM:To study whether over-starvation aggravates intestinal mucosal injury and promotes bacterial and endotoxin translocation in a high-altitude hypoxic environment.METHODS:Sprague-Dawley rats were exposed to hy-pobaric hypoxia at a simulated altitude of 7000 m for 72 h.Lanthanum nitrate was used as a tracer to detect intestinal injury.Epithelial apoptosis was observed with terminal deoxynucleotidyl transferase dUTP nick end labeling staining.Serum levels of diamino oxidase(DAO),malondialdehyde(MDA),glutamine(Gln),superoxide dismutase(SOD) and endotoxin were measured in intestinal mucosa.Bacterial translocation was detected in blood culture and intestinal homogenates.In addition,rats were given Gln intragastrically to observe its protective effect on intestinal injury.RESULTS:Apoptotic epithelial cells,exfoliated villi and inflammatory cells in intestine were increased with edema in the lamina propria accompanying effusion of red blood cells.Lanthanum particles were found in the intercellular space and intracellular compartment.Bacterial translocation to mesenteric lymph nodes(MLN) and spleen was evident.The serum endotoxin,DAO and MDA levels were significantly higher while the serum SOD,DAO and Gln levels were lower in intestine(P< 0.05).The bacterial translocation number was lower in the high altitude hypoxic group than in the high altitude starvation group(0.47±0.83 vs 2.38±1.45,P<0.05).The bacterial translocation was found in each organ,especially in MLN and spleen but not in peripheral blood.The bacterial and endotoxin translocations were both markedly improved in rats after treatment with Gln.CONCLUSION:High-altitude hypoxia and starvation cause severe intestinal mucosal injury and increase bacterial and endotoxin translocation,which can be treated with Gln.
基金supported by grants from the“Basic research Projects”from Qinghai Science and Technology Department of China(2019-ZJ-7059)“Basic research Projects”from Qinghai Science and Technology Department of China(2016-ZJ-924Q)。
