【作者】 林海；

【导师】 周红；

【作者基本信息】 第三军医大学 ， 外科学， 2004， 硕士

【摘要】 目的 肠道是对缺血、缺氧损伤敏感的器官之一，其缺氧性损伤普遍存在于严重烧创伤的病理生理过程中，在严重烧创伤中发生最早、恢复最迟。严重烧伤后，肠粘膜屏障损害、免疫功能受抑制、肠道菌群紊乱，肠道中的微生物和内毒素可通过受损的肠粘膜屏障进入体循环，形成肠源性感染，导致全身性炎症反应综合征（SIRS）乃至多器官功能不全（MODS）的发生。 线粒体作为能量转换的细胞器对缺血、缺氧等因素十分敏感，缺血、缺氧损伤可致线粒体结构和功能障碍，进一步导致肠粘膜损伤的发生。近来研究发现ATP依赖性钾通道(K_ATP)开放剂对心肌缺血、缺氧性损伤具有保护作用，其作用靶点可能在线粒体膜ATP依赖性钾通道(mitoK_ATP)，但却未见该类药物对肠粘膜缺血、缺氧性损伤具有保护作用的报道。 因此本研究旨在通过实验观察mitoK_ATP开放剂吡那地尔（Pin）对肠粘膜上皮细胞是否具有保护作用，寻找严重烧创伤致肠道缺血、缺氧性损伤的防治药物。 方法 ①建立活性氧损伤人肠上皮细胞的体外模型，运用MTT法、免疫组化法、激光共聚焦法，观察活性氧损伤肠上皮细胞线粒体的整体功能、细胞色素C的释放、线粒体膜电位的变化及吡那地尔对肠上皮细胞线粒体的保护作用；②复制大鼠30％TBSA Ⅲ度烫伤模型，观察大鼠血浆和肠粘膜组织ROS、MDA、SOD的含量，肠粘膜组织细胞色素C的释放、线粒体的呼吸功能、病理形态改变以及吡那地尔的保护作用。 结果 ①成功建立活性氧损伤肠上皮细胞的体外模型；②体外实验表明，采用高浓度（4mmol／L）及低浓度（400lμmol／L）H₂O₂损伤肠上皮细胞后，细胞线粒体整体功能下降、细胞色素释放增加、线粒体膜电位降低，吡那地尔可显著改善线粒体功能；③动物实验结果表明，烫伤大鼠血浆和肠粘膜组织ROS、MDA呈现不同程度增高、SOD降低，线粒体RCR下降、线粒体肿胀明显，上述变化在伤后6h尤为明显，吡那地尔可显著改善上述指标、减轻肠粘膜组织的病理学改变。第三军医大学硕士学位论文结论①毗那地尔对活性氧损伤的肠上皮细胞具有显著保护作用; ②毗那地尔对严重烧伤早期的肠粘膜组织具有显著保护作用。更多还原

【Abstract】 Object: The intestine is one of the most sensitive organs on ischemia and anoxia. Since intestinal mucous membrane barrier was damaged after burn, microorganism and endotoxin entered into blood from intestinal tract, which easily resulted in systemic inflammatory response syndrome (SIRS) and even more, multiple organ dysfunction syndrome (MODS).Mitochondrion, an organelle for translating energy, is very sensitive to ischemia and anoxia, which can cause disturbance of mitochondrial structure and function.Recent studies found that ATP sensitive K+ channel (KATP) opener could protect myocardia from ischemia and hypoxia. Its pharmacological role targeted myocardial mitochondrion membrane KATP channel (mitoKArp). However, there wasn’t any report about this kind of protection on intestinal mucous membrane damaged by ischemia and anoxia.Therefore, this study aimed at searching for pharmacological protection of pinacidil (Pin), a mitoKATp opener, on intestinal mucous membrane damaged by severe burn.Methods:(1) After establishing a model using intestinal epithelial cells (HIC) damaged by reactive oxygen species, intestinal epithelial cells mitochondrial allomeric function, cytochrome C release, mitochondrial membrane potential and pinacidil protection on intesting epithelial cells mitochondria were observed.(2) After establishing 30% TBSA III0 burn model, ROS, MDA and SOD in plasma and intestinal mucous as well as cytochorme C, mitochondrial respiratory function and pathological morphology changes in rats treated or un-treated with pinacidil were observed.Results:(1) In vitro, It was found that HIC cells’ mitochondrial functions descented; cytochrome C release increased, while mitochondrial membrane potential reduced. However, pinacidil could improve mitochondrial function significantly.(2) In burnt rats, ROS and MDA elevated in plasma and intestinal mucosa. SOD and mitochondrial RCR decreased. Mitochondrion swelling occurred in burned rats, too. The remarkable changes appeared at 6 hour-point after burn. Pinacidil could improvemitochondrial functions and decrease pathomorphology damage of intestinal mucosa.Conclusion:(1) Pinacidil could protect intestinal epithelial cells from reactive oxygen species’ injury in vitro(2) Pinacidil could significantly protect intestinal mucous membrane at early stage in burnt rats in vivo.更多还原