瘦素、食欲素-A在肝、肠损伤介导的内环境紊乱中的变化及对脏器功能的影响

发布时间：2018-01-07 09:38

本文关键词：瘦素、食欲素-A在肝、肠损伤介导的内环境紊乱中的变化及对脏器功能的影响　出处：《中国人民解放军军医进修学院》2008年博士论文　论文类型：学位论文

【摘要】： 瘦素(Leptin)是一种主要作用为抑制摄食、促进能量消耗的活性因子,食欲素-A(Orexin-A)是一种主要作用为促进摄食、抑制能量消耗的短肽。目前研究发现Leptin可通过腺苷酸活化蛋白激酶、过氧化物酶体增殖物激活受体-α等途径抑制糖原合成、促进脂肪酸氧化,Orexin-A在能量代谢中的作用及其在一定条件下的表达水平都与Leptin相反,而且它们与糖皮质激素、交感神经兴奋性、炎症介质都存在联系,提示它们可能参与调控创伤、炎症、感染后的内环境紊乱。由于肝脏、肠道是营养吸收、能量代谢的重要器官,我们考察了Leptin、Orexin-A的表达水平在肝、肠损伤时发生的变化,分析了这些变化与重要脏器的结构损伤、功能改变之间的联系,并探讨了创伤后营养支持、激素干预对它们的表达水平和脏器功能的影响。 1.肝缺血/再灌注损伤后Leptin、Orexin-A表达水平的变化及与脏器功能的联系建立大鼠70%肝缺血/再灌注损伤模型,设立假手术、缺血60 min后不同时间的再灌注组。采用放免法检测Leptin、Orexin-A在外周血、各自的核心分泌器官(脂肪、下丘脑)的蛋白水平;采用苏木素-伊红染色考察与自由基损伤、能量代谢密切相关的外周脏器(肺、肝)的损伤情况,以试剂盒检测血清髓过氧化物酶、丙氨酸氨基转移酶作为肺、肝功能指标,以血清总抗氧化能力、葡萄糖作为抗自由基损伤、能量储备的代谢指标;采用免疫组化检测Leptin、Orexin-A在肺、肝的蛋白表达;采用逆转录-聚合酶链式反应检测Leptin、Orexin-A及其受体在下丘脑、脂肪、肺、肝的mRNA表达。从纵向时序变化的角度考察它们的表达改变与脏器功能的联系。结果显示,血清Leptin、总抗氧化能力和葡萄糖于再灌注后期显著升高,脂肪Leptin蛋白水平在再灌注早期显著升高,血浆、下丘脑Orexin-A蛋白水平无显著变化。再灌注后期肺、肝损伤情况及其功能指标显著改善。肺Leptin、Orexin-A蛋白表达显著降低,肝Leptin蛋白表达于再灌注早期、后期显著升高,而肝Orexin-A蛋白表达变化与之相反。各脏器Leptin、Orexin-A mRNA表达的变化趋势非常相似,其受体mRNA表达紧随它们而变化。 2.营养支持、激素干预对脓毒症时Leptin、Orexin-A表达水平及脏器功能的影响第一部分的实验结果提示Leptin、Orexin-A的表达水平受能量代谢的调控,与下丘脑-脂肪-肺/肝这条功能主线存在显著联系。由于脂肪乳、胰岛素、雌二醇与能量代谢、创伤修复都存在联系,我们设想利用它们来干预创伤后的脂肪酸代谢、糖代谢和激素分泌,可能会对Leptin、Orexin-A的表达水平及脏器功能产生影响。建立大鼠盲肠结扎穿孔(CLP)致脓毒症模型,设立假手术、CLP模型和三个药物干预组。检测CLP后12 h时Leptin、Orexin-A在外周血、肺、肝的蛋白表达与它们在下丘脑、脂肪、肺、肝的mRNA表达,考察肺、肝的损伤情况以及脏器功能、代谢指标的变化。从横向干预差异的角度考察它们的表达改变与脏器功能的联系。结果显示,各组血清Leptin、总抗氧化能力、葡萄糖无显著变化,CLP模型、CLP+脂肪乳的血浆Orexin-A显著升高。CLP模型、CLP+胰岛素的血清髓过氧化物酶显著升高,CLP+胰岛素的血清丙氨酸氨基转移酶显著降低。CLP模型、CLP+雌二醇的肺、肝损伤较明显,CLP+脂肪乳、CLP+胰岛素显著改善。各组肺、肝Leptin、Orexin-A蛋白表达和各脏器Leptin、Orexin-AmRNA表达的变化不一。CLP+脂肪乳的下丘脑、脂肪Leptin mRNA表达显著升高,肺、肝Leptin mRNA表达与蛋白表达均显著降低。上述两部分的实验结果显示:Leptin、Orexin-A在肝、肠损伤介导的内环境紊乱中发生不同程度的变化,与重要脏器的结构损伤、功能改变联系密切。脂肪乳、胰岛素显著减轻肺、肝损伤,而雌二醇无明显的改善作用。虽然三种干预药物对Leptin、Orexin-A的表达水平具有不同的影响,但却提示了Leptin、Orexin-A参与三种干预药物的脏器效应通路,值得我们进一步研究。探索以Leptin、Orexin-A为核心的神经-内分泌调节机制有助于研发针对相关疾患的内源性干预方法。
[Abstract]:Leptin (Leptin) is a main function of inhibiting food intake, promoting activity factor of energy consumption, orexin -A (Orexin-A) is a major role for improving appetite, inhibiting peptide energy consumption. The current study found by Leptin amp activated protein kinase, peroxisome proliferator activated receptor alpha the inhibition of glycogen synthesis, promoting fatty acid oxidation, the role of Orexin-A in energy metabolism and its expression level under certain conditions are contrary to the Leptin, and they with glucocorticoid, sympathetic nerve excitability, inflammatory mediators are linked, suggesting that they may be involved in the regulation of inflammation, trauma, infection after internal environment disorder because the liver is an important organ of intestinal absorption of nutrients, energy metabolism, we investigated the effect of Leptin, the expression level of Orexin-A in the liver, change of intestinal injury, analyzes the changes and important organs The relationship between structural damage, functional changes, and posttraumatic nutrition support, and the effects of hormone intervention on their expression level and organ function are discussed.
1. changes of Leptin, Orexin-A expression level and relationship with organ function after liver ischemia / reperfusion injury
To establish the model of rat model of 70% hepatic ischemia / reperfusion injury, sham operation, ischemia 60 min at different time after reperfusion group by radioimmunoassay. Leptin, Orexin-A in peripheral blood, their core secretory organs (fat, hypothalamus) protein level; by hematoxylin eosin staining and free inspection radical damage, energy metabolism is closely related to the peripheral organs (lung and liver) injury, to detect serum myeloperoxidase kit, alanine aminotransferase as lung, liver function index, serum total anti-oxidation capacity, glucose as anti free radical damage, metabolism of energy reserves; by immunohistochemical detection of Leptin the expression of Orexin-A in lung, liver, protein; Leptin was detected by using reverse transcriptase polymerase chain reaction, Orexin-A and its receptor in the hypothalamus, fat, lung, liver mRNA expression. From the perspective of longitudinal temporal change their expression changes Contact with the function of the viscera.
The results showed that serum Leptin, total antioxidant capacity and glucose in late reperfusion significantly increased fat Leptin protein levels significantly increased in early reperfusion plasma, no significant changes in Orexin-A protein levels. Late reperfusion lung injury and liver function index improved significantly. The lung Leptin, Orexin-A protein expression decreased significantly, liver the expression of Leptin protein in the early phase of reperfusion, increased significantly in the later period, while the liver Orexin-A protein expression on the contrary. The organs of Leptin, the change trends of the Orexin-A expression of mRNA is very similar to that of its receptor mRNA expression followed by their changes.
2. effects of nutritional support, hormone intervention on Leptin, Orexin-A expression and organ function in sepsis
The first part of the experiment results suggest that Leptin, the expression level of Orexin-A by the regulation of energy metabolism, are significantly associated with hypothalamic fatty lung / liver function as the main line. The fat milk, insulin, estradiol and energy metabolism, wound repair are linked, we envision the use of their fatty acids metabolic intervention after trauma, glucose metabolism and hormone secretion, may affect the expression level of Leptin, Orexin-A and organ function. The establishment of rat cecal ligation and perforation (CLP) sepsis model, sham operation, CLP model and three drug intervention group. The detection of CLP at 12 h after Leptin, Orexin-A in peripheral blood the expression of the liver, lung, protein and fat in hypothalamus, liver, lung, the expression of mRNA on lung, liver injury and organ function, changes of metabolic parameters. The influences of expression changes and their organ from different angle transverse intervention Yes, I can.
The results showed that the serum Leptin, total antioxidant capacity, glucose had no significant change, CLP model, plasma Orexin-A CLP+ fat emulsion increased significantly.CLP model, serum myeloperoxidase CLP+ insulin significantly increased serum alanine transaminase in CLP+ insulin significantly decreased the.CLP model, CLP+ estradiol lung, liver injury obviously, CLP+ fat milk, CLP+ insulin significantly improved. Lung, liver Leptin, Orexin-A protein expression and organs of Leptin, the expression of Orexin-AmRNA is not a.CLP+ fatty milk fat Leptin hypothalamus, the expression of mRNA was significantly increased, lung, liver Leptin mRNA expression and protein expression were significantly decreased.
The two part of the experimental results showed that Leptin, Orexin-A in liver, changes of intestinal injury induced internal disorders, and the damage of important organs, function change closely. Fat milk, insulin significantly reduced the lung and liver injury, while estradiol has no obvious improvement. Although three drug intervention on Leptin, have different effects on the expression level of Orexin-A, it suggests that Leptin Orexin-A is involved in organ effect pathway three intervention drugs, which is worthy of further investigation. To explore Leptin, Orexin-A as the core of the neuro endocrine mechanism contributes to the development of endogenous intervention methods on relative diseases.

【学位授予单位】：中国人民解放军军医进修学院
【学位级别】：博士
【学位授予年份】：2008
【分类号】：R363

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