右美托咪定对COPD大鼠机械通气时肺脏的保护作用

发布时间：2018-04-23 04:23

本文选题：右美托嘧啶 + COPD大鼠　；参考：《郑州大学》2014年硕士论文

【摘要】：背景与目的慢性阻塞性肺疾病（Chronic obstructive pulmonary disease,COPD）是一种以气流受限为特征、呈不完全可逆并伴有肺功能逐渐下降的慢性呼吸系统疾病。流行病学调查显示，全球40岁以上的男性中有10%患有COPD。由于环境污染的加剧和吸烟等因素的影响，其发病人数仍在剧增，在发展中国家其发病率和死亡率增长速度较发达国家增加迅速。目前研究认为其发病机制主要为炎症反应、氧化应激和蛋白酶-抗蛋白酶失衡等作用导致肺实质和气道的病变[1]。机械通气是COPD患者急性加重期和全身麻醉过程中必不可少的辅助通气措施，在保证机体氧供的同时，亦可加重患者的肺损伤。目前在机械通气肺保护的研究中，主要集中于不同模式的机械通气策略，以及糖皮质激素等药物的应用，其目的是减少外界刺激损伤，阻断炎症反应和氧化应激的影响。盐酸右美托咪定是目前广泛应用于ICU和麻醉科的一种新型的高选择性α2-肾上腺素受体激动剂，具有镇静、镇痛、催眠、抗交感和抑制血浆中儿茶酚胺释放等作用。除此之外，近年的多项研究表明右美托咪定在神经保护[2-4]、心肌保护[5，6]、肾脏保护[7]等重要器官的保护中有重要的作用。目前，对于右美托咪定对肺脏的保护作用研究较少。本研究采用气管内滴加脂多糖联合被动香烟吸入法建立COPD大鼠模型，然后给予2h常规潮气量机械通气，通过不同剂量右美托咪定的干预处理，观察右美托咪定对机械通气COPD大鼠氧化应激的影响，探讨盐酸右美托咪定对COPD大鼠机械通气时肺脏的作用机制。材料与方法雄性清洁级成年Wistar大鼠48只，平均体重为180±20g，购自河南省实验动物中心。将所购大鼠随机分为6组：正常组：D组、D1组，模型组：C组、C1组、C2组、C3组。模型组C组、C1组、C2组、C3组参照宋一平[8]方法复制COPD大鼠模型28d，正常组D组和D1组单纯饲养28d。行大鼠肺功能检测，评价模型复制成功与否。除D组和C组以外，每组大鼠行机械通气2h，潮气量设置为8ml/kg。C2组和C3组在通气过程中分别给予1.0μg/kg/h和5.0μg/kg/h的右美托咪定稀释液。D1组和C1组注射等量生理盐水。通气结束后各组大鼠取腹主动脉血3ml，静止30min后离心取上清液，待做ELISA测定IL-β、TNF-α含量；取肺组织：左肺测定湿重后70℃恒温箱放置48h至恒重，测干湿比W/D，右肺上叶和中叶液氮冷冻30min后置于-70℃冰箱保存，右肺上叶待做ELISA测定8-iso-PGF2α，右肺下叶石蜡包埋后切片待做免疫组化和HE染色。统计学分析采用SPSS17.0统计分析软件进行处理。符合正态分布的计量资料采用均数±标准差（X±S）表示，两组间比较采用t检验，多组间比较采用单因素方差分析，两两比较方差齐者采用LSD法，不齐者采用Dunnett’s t-test。显著性检验水准取α=0.05。结果 1肺组织W/D变化与正常组D组比较，模型组C组大鼠W/D增高，差异有统计学意义（P＜0.05）。COPD模型组C1组、C2组、C3组与正常组D1组大鼠比较，W/D的水平明显升高，差异有统计学意义（P＜0.05）。C1组、C2组、C3组与正常组C组大鼠比较，W/D的水平明显升高，差异有统计学意义（P＜0.05）。C1组与D1组相比，W/D明显增加，差异有统计学意义（P＜0.05）。C2组与C1组相比，W/D明显下降，差异有统计学意义（P＜0.05）。C3组与C2组相比，W/D明显下降，差异有统计学意义（P＜0.05）。 2血清中TNF-α和IL-1β的变化与正常组D组比较，模型组C组大鼠血清TNF-α和IL-1β明显增高。D1组与D组相比，两者表达量有所增加，但差异无统计学意义（P＞0.05）。COPD模型组C1组、C2组、C3组与正常组D1组大鼠比较，血清中IL-1β、TNF-α的水平明显升高，差异有统计学意义（P＜0.05）。C1组、C2组、C3组与C组大鼠比较，血清中IL-β、TNF-α的水平明显升高，差异有统计学意义（P＜0.05）。C2组与C1组相比，两者表达量明显下降，差异有统计学意义（P＜0.05）。C3组与C2组相比，两者含量明显下降，差异有统计学意义（P＜0.05）。 3肺组织8-异前列腺素变化正常组大鼠D1组与D组相比，其表达量明显增加，差异有统计学意义（P＜0.05）。COPD模型组C1组、C2组、C3组与正常组D1组大鼠比较，肺组织匀浆中8-iso-PGF2α的水平明显升高，差异有统计学意义（P＜0.05）。C1组、C2组、C3组与正常组C组大鼠比较，肺组织匀浆中8-iso-PGF2α的水平明显升高，差异有统计学意义（P＜0.05）。C2组与C1组相比，其表达量下降，但差异无统计学意义（P＞0.05）。C3组与C2组相比，其含量明显下降，差异有统计学意义（P＜0.05）。 4肺组织结构变化 HE染色显示结果为D组和D1组大鼠肺组织结构基本正常，肺纹理清晰，无肺大泡，但D1组大鼠肺组织有少许炎症细胞浸润。C组、C1组、C2组、和C3组肺纹理紊乱，，有明显肺大泡生成，且有大量炎症细胞浸润。 5肺组织Nrf2和HO-1mRNA表达与D组比较，C组大鼠肺组织Nrf2和HO-1mRNA表达水平增高，差异有统计学意义。机械通气2h后，C1组、C2组、C3组大鼠肺组织Nrf2和HO-1mRNA表达水平显著高于C组，差异有统计学意义。与C1组比较，C2组大鼠肺组织Nrf2和HO-1mRNA表达水平增加，差异无统计学意义。与C2组比较，C3组大鼠肺组织Nrf2和HO-1mRNA表达水平增加，差异有统计学意义。 6肺组织Nrf2和HO-1蛋白表达与D组比较，C组大鼠肺组织中Nrf2和HO-1蛋白表达增高，差异有显著性。与C组比较，C1组，C2组，C3组大鼠肺组织中Nrf2和HO-1蛋白表达显著增强，差异具有显著性。与C1组比较，C2组大鼠肺组织中Nrf2和HO-1蛋白表达增加，差异无显著性。与C2组比较，C3组大鼠肺组织Nrf2和HO-1蛋白表达增加，有明显差异。结论 1、机械通气对正常组大鼠肺脏氧化应激和炎症反应无明显影响，但可加重COPD大鼠肺脏的氧化应激反应和炎症反应，加重肺损伤。 2、机械通气过程中，右美托咪定可以通过降低炎症因子表达和增强抗氧化应激作用减轻COPD大鼠肺损伤；且持续输注5.0μg/kg/h的盐酸右美托咪定较1.0μg/kg/h对COPD大鼠肺保护作用强。
[Abstract]:Background and purpose
Chronic obstructive pulmonary disease (Chronic obstructive pulmonary disease, COPD) is a chronic respiratory disease characterized by airflow limitation, which is not completely reversible with a gradual decline in lung function. Epidemiological investigation shows that 10% of men over 40 years of age suffer from the aggravation of environmental pollution and smoking and other factors of COPD.. The incidence of morbidity and mortality in developing countries is increasing rapidly in developing countries. It is believed that the main pathogenesis is inflammatory reaction, oxidative stress and protease anti protease imbalance in the lung parenchyma and airway disease [1].
Mechanical ventilation is an essential auxiliary ventilation measure in the acute exacerbation and general anesthesia of COPD patients. It can also aggravate the lung injury of the patients while ensuring the oxygen supply of the body. In the study of mechanical ventilation protection, the main focus is on the different modes of mechanical ventilation strategy and the application of glucocorticoid. It is to reduce external irritation injury, block inflammatory reaction and oxidative stress.
Dexmeimidine hydrochloride is a new type of high selective alpha 2- adrenergic agonist, which is widely used in ICU and anesthesiology. It has the effects of sedative, analgesic, hypnotic, anti sympathetic and inhibiting the release of catecholamine in plasma. In addition, a number of studies in recent years have shown that dexmedetomidin in neuroprotective [2-4] and myocardial protection of [5,6], Kidney plays an important role in protecting [7] and other important organs.
At present, there are few studies on the protective effect of dexmedetomidine on the lung. The COPD rat model was established by intratracheal drops plus lipopolysaccharide combined with passive cigarette inhalation, and then 2H conventional tidal volume mechanical ventilation was given, and right metomomidine was treated by different doses of dexmedetomidine to observe the oxidation of COPD rats with mechanical ventilation. To explore the mechanism of dexmedetomidine hydrochloride on the lungs of COPD rats during mechanical ventilation.
Materials and methods
48 adult male Wistar rats, with an average weight of 180 20g, were purchased from the experimental animal center of Henan province. The rats were randomly divided into 6 groups: normal group, group D, group D1, model group, group C, C1 group, C2 group, C3 group. The model group C group, C1 group, C2 group, C3 group refer to Song Yiping method, normal group and simple group simple 28d. rats were fed with lung function test to evaluate the success of model replication. Except for group D and group C, the rats in each group underwent mechanical ventilation 2H. The tidal volume was set in 8ml/kg.C2 group and C3 group in group 8ml/kg.C2 and 5 micron g/kg/h in.D1 group and C1 group, respectively. The rat aorta blood 3ml was taken from the abdominal aorta, and the supernatant was centrifuged after static 30min. The content of IL- beta and TNF- alpha was measured by ELISA. The lung tissue: the left lung was measured at 70 C after wet weight and placed 48h to constant weight, the dry and wet ratio W/D, the right upper lobe and the middle lobe liquid nitrogen frozen 30min were kept in the -70 centigrade refrigerator, and the right lung lobe was waiting for ELISA to determine 8-iso-PGF2 A and right lung. The paraffin embedded sections of lower lobe were stained with immunohistochemistry and HE staining.
SPSS17.0 statistical analysis software was used to deal with it. The measurement data conforming to normal distribution were represented by mean number + standard deviation (X + S). The two groups were compared with t test, the multiple groups were compared with single factor analysis of variance, and 22 were compared with the LSD method, and the non homogeneous people adopted the Dunnett 's t-test. significance test to take the alpha =0.05..
Result
1 W/D changes in lung tissue
Compared with the normal group D group, the model group C group W/D increased, the difference was statistically significant (P < 0.05).COPD model group C1 group, C2 group, C3 group and normal group D1 group compared with the normal group, the level of W/D significantly increased, the difference was statistically significant (P < 0.05).C1 group, compared with the normal group rats, the level was significantly higher, the difference was statistically significant. P < 0.05).C1 group compared with group D1, W/D was significantly increased, the difference was statistically significant (P < 0.05) the W/D decreased significantly in.C2 group and C1 group, and the difference was statistically significant (P < 0.05). The W/D significantly decreased in.C3 group and C2 group, and the difference was statistically significant (0.05).
Changes of serum TNF- A and IL-1 beta in 2 serum
Compared with the normal group D group, the serum TNF- A and IL-1 beta in the C group of the model group were significantly higher than those in the D group. The difference was not statistically significant (P > 0.05).COPD model group C1 group, C2 group, C3 group compared with the normal group rats, the level of serum beta and alpha was significantly higher, the difference was statistically significant (0.05). In group.C1, group C2, group C3 and group C, the level of IL- beta, TNF- alpha in serum was significantly higher, the difference was statistically significant (P < 0.05) compared with the C1 group, the expression of the two groups decreased significantly (P < 0.05) the difference was significantly lower than that in the C2 group, and the difference was statistically significant (0.05).
Changes of 8- isoprostaglandin in 3 lung tissues
The expression of D1 in the normal group was significantly higher than that in the D group, the difference was statistically significant (P < 0.05).COPD model group C1, C2, C3 group and normal group D1 group, the level of 8-iso-PGF2 alpha in lung homogenate was significantly higher, the difference was statistically significant (P < 0.05).C1 group, C2 group and normal group rats, lung tissue homogenization The level of 8-iso-PGF2 alpha in the pulp increased significantly (P < 0.05) (P < 0.05) the expression of.C2 group was lower than that of the C1 group, but the difference was not statistically significant (P > 0.05), the content of.C3 group was significantly lower than that of the C2 group, and the difference was statistically significant (P < 0.05).
4 changes in the structure of lung tissue
HE staining showed that the lung tissue structure was normal in group D and group D1, with clear lung texture and no pulmonary bullae, but there were a few inflammatory cells infiltrating.C group in group D1, C1 group, C2 group, and C3 group with lung texture disorder, obvious pulmonary bullae formation and large number of inflammatory cells infiltrating.
Expression of Nrf2 and HO-1mRNA in 5 lung tissues
Compared with group D, the expression level of Nrf2 and HO-1mRNA in lung tissue of rats in group C was higher, and the difference was statistically significant. After 2h of mechanical ventilation, the expression level of Nrf2 and HO-1mRNA in lung tissue of C1 group, C2 group and C3 group was significantly higher than that in C group, and the difference was statistically significant. Significance. Compared with group C2, the expression level of Nrf2 and HO-1mRNA in lung tissue of C3 group increased, the difference was statistically significant.
Expression of Nrf2 and HO-1 protein in 6 lung tissues
Compared with group D, the expression of Nrf2 and HO-1 protein in lung tissue of group C rats increased significantly. Compared with group C, the expression of Nrf2 and HO-1 proteins in lung tissues of group C1, C2 and C3 group increased significantly. The expression of Nrf2 and HO-1 protein in rat lung tissue increased significantly.
conclusion
1, mechanical ventilation has no obvious effect on the oxidative stress and inflammatory response in the lungs of normal rats, but can aggravate the oxidative stress reaction and inflammatory response in the lungs of COPD rats and aggravate the lung injury.
2, in the process of mechanical ventilation, dexmedetomidine can reduce the lung injury in COPD rats by reducing the expression of inflammatory factors and enhancing the anti oxidative stress, and the protective effect of right metomomidine on the lung of COPD rats is stronger than that of 1 u g/kg/h.

【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R614

【参考文献】