右美托咪定对脂多糖诱导的小鼠急性肺损伤保护作用的研究

发布时间：2018-04-25 20:30

本文选题：急性肺损伤 + 右美托咪定　；参考：《滨州医学院》2015年硕士论文

【摘要】：目的：右美托咪定是一种新型的α2受体激动剂,因其具有镇痛镇静的效果,被越来越多的应用到重症监护病房,并且它作为一种麻醉辅助用药得到广泛应用。目前,右美托咪定的抗炎机制成为研究的热点,本文探讨右美托咪定对于脂多糖诱导的小鼠急性肺损伤的抗炎作用及可能的分子机制。方法：50只清洁级小鼠被随机分为五组：正常组(Control组)、模型组(LPS组)、右美托咪定预处理组Dex (25μg/kg)+LPS组和Dex (50μg/kg)+LPS组、地塞米松预处理对照组(DXM+LPS组)。小鼠被腹腔注射5mg/kg脂多糖建立急性肺损伤模型,与此同时,Control组小鼠腹腔注射生理盐水,右美托咪定和地塞米松(1mg/kg)分别于脂多糖处理之前1小时腹腔注射。脂多糖处理后6小时,对小鼠行支气管肺泡灌洗,并取血、取小鼠的肺组织。小鼠的部分肺组织被用来测定湿干比重；石蜡切片后染色,显微镜下分析肺组织病理学改变；用Elisa试剂盒检测支气管肺泡灌洗液和血浆中细胞因子；BCA方法检测支气管肺泡灌洗液中总的蛋白含量；利用RT-PCR技术检测肺组织中相关mRNA的表达；Westorn Blot方法被用来检测肺组织中MAPK信号通路以及p38 MAPK-HSP27通路相关蛋白的表达。结果：实验结果表明,与正常组比较,LPS组小鼠表现出明显的肺水肿和肺组织病理学改变,而右美托咪定预处理组和地塞米松处理组小鼠的肺组织水肿程度明显减轻,肺组织病理学改变减轻,肺组织病理学评分明显降低。同时,与Control组比较,LPS组的小鼠支气管肺泡灌洗液中蛋白含量和细胞因子(TNF-α,IL-1β)的浓度增加明显,而右美托咪定和地塞米松处理组小鼠的上述指标明显减少。同时,小鼠血浆中的细胞因子(TNF-α,IL-1β)含量也显示出LPS组小鼠的比Control组明显增加,而Dex (25μg/kg)+LPS组和Dex (50μg/kg)+LPS组小鼠血浆中的TNF-α和IL-1β比LPS组明显的减少,DXM+LPS组小鼠血浆中的细胞因子含量与右美托咪定组的相近,比LPS组的含量减少明显。PCR结果也表明LPS组肺组织中细胞因子(TNF-α,IL-6) mRNA的表达量显著升高而右美托咪定和地塞米松预处理后的表达量明显减少。另外,免疫印迹的条带分析显示右美托咪定能够抑制MAPK信号通路以及p38 MAPK-HSP27通路的激活。结论：右美托咪定显著地减轻脂多糖导致的小鼠急性肺损伤,其机制可能是右美托咪定抑制MAPK相关信号通路的激活从而减轻炎症反应。因此,右美托咪定可能会对治疗脓毒症导致的急性肺损伤患者提供新的方向。
[Abstract]:Objective: Dexmedetomidine is a new type of alpha 2 receptor agonist. Because of its analgesic and sedative effect, it has been used more and more in intensive care unit, and it is widely used as a kind of anesthetic adjuvant. Right metomomidine has become a hot spot. The anti-inflammatory effect and possible molecular mechanism of sugar induced acute lung injury in mice. Methods: 50 clean mice were randomly divided into five groups: normal group (group Control), model group (group LPS), Dex (25 u g/kg) +LPS group and Dex (50 g/kg) +LPS group, dexamethasone preconditioning group (DXM+LPS group). Mice were treated with abdominal cavity. 5mg/kg lipopolysaccharide was injected into an acute lung injury model. At the same time, rats in group Control were intraperitoneally injected with saline, right metomomidin and dexamethasone (1mg/kg) were intraperitoneally injected 1 hours before lipopolysaccharide treatment. 6 hours after lipopolysaccharide treatment, the mice were treated with bronchoalveolar lavage, and the lung tissue of mice was taken from the mice. The lung tissue was used to determine the specific gravity of the wet dry; the paraffin section was stained, the pathological changes of lung tissue were analyzed under the microscope; the cytokine in bronchoalveolar lavage fluid and plasma were detected by Elisa kit; the total protein content in the bronchoalveolar lavage fluid was detected by the BCA method; and the expression of related mRNA in the lung tissue was detected by RT-PCR technique. The Westorn Blot method was used to detect the MAPK signaling pathway in lung tissue and the expression of p38 MAPK-HSP27 pathway related proteins. Results: experimental results showed that compared with the normal group, the mice of group LPS showed obvious pulmonary edema and pulmonary histopathological changes, while the lung tissues of dexmeimidine preconditioning group and dexamethasone treated group were compared with the normal group. The degree of edema was obviously reduced, the pathological changes of lung tissue were reduced, and the score of lung histopathology decreased obviously. At the same time, the concentration of protein and cytokine (TNF- alpha, IL-1 beta) in the bronchoalveolar lavage fluid of the LPS group increased significantly compared with the Control group, but the above indexes in the right metomomidin and dexamethasone treatment group were significantly reduced. At the same time, the content of cytokine (TNF- alpha, IL-1 beta) in the mice plasma also showed that the LPS group was significantly higher than the Control group, while the TNF- alpha and IL-1 beta in the plasma of Dex (25 u g/kg) +LPS group and Dex (50 g/kg) +LPS group were significantly lower than those in the group. The decrease of the content of.PCR in group LPS also showed that the expression of cytokine (TNF-, IL-6) mRNA in the lung tissue of LPS group was significantly increased and the expression of dexmedetomidin and dexamethasone decreased significantly. Conclusion: dexmedetomidin significantly alleviates acute lung injury induced by lipopolysaccharide in mice. The mechanism may be that dexmedetomidine inhibits the activation of MAPK related signaling pathways and thus alleviates the inflammatory response. Therefore, dexmedetomidine may provide a new direction for patients with acute lung injury caused by sepsis.

【学位授予单位】：滨州医学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R614

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