【作者】 宋智；

【导师】 罗万俊；

【作者基本信息】 中南大学 ， 心胸外科， 2009， 硕士

【摘要】 目的:通过检测肺功能的变化,支气管肺泡灌洗液(BALF)中白细胞和乳酸脱氢酶(LDH),血清中超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量,免疫组织化学方法检测肺组织SP-A表达水平及HE染色观察肺组织病理改变来研究非创伤性肢体缺血预处理(N-LIP)对脂多糖诱导大鼠急性肺损伤的保护作用。方法:将15只SD雌性大鼠随机分为对照组、急性肺损伤组(ALI组)、急性肺损伤+非创伤性双下肢缺血预处理组(ALI+N-LIP组)。戊巴比妥钠腹腔注射麻醉,ALI+N-LIP组用止血带捆绑双下肢,阻断血流5min,再开放5min,反复3次,每次捆绑以双下肢紫绀、捆绑下方腹股沟处摸不到股动脉搏动为准;之后ALI组和ALI+N-LIP组分别予以腹腔注射脂多糖(4mg/kg),对照组注射等量生理盐水;1h后用Buxco有创肺功能仪,以乙酰甲胆碱(methacholine,Mch)0.39ng/mL、0.78ng/mL、1.56ng/mL、3.12ng/mL依次激发,检测大鼠气道阻力(AR)、动态肺顺应性(Cdyn)的变化,收集肺泡灌洗液(BALF),取血及肺组织。细胞计数法测定BALF中白细胞(WBC)数量,全自动生化分析仪检测BALF中乳酸脱氢酶(LDH)含量,比色法测血清中超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量,免疫组织化学方法检测肺组织中肺泡表面活性物质相关蛋白-A(pulmonary surfactant associatedprotein,SP-A)的表达水平,HE染色观察肺组织病理变化。结果:1.较正常对照组相比,Mch激发后ALI组气道阻力(AR)明显增高(P＜0.01),动态肺顺应性(Cdyn)明显减弱(P＜0.01)。ALI+N-LIP组大鼠气道阻力(AR)的增高程度(P＜0.01)、动态顺应性(Cdyn)的减弱程度(P＜0.01)均明显小于ALI组。2.支气管肺泡灌洗(bronchoalveolar lavage fluid,BALF)中,ALI组的白细胞数(P＜0.01)、LDH含量(P＜0.01)比对照组明显升高;ALI+N-LIP组BALF中白细胞数(P＜0.01)和LDH含量(P＜0.01)也增高但增高程度均明显小于ALI组(P＜0.05)。3.ALI组血清中超氧化物歧化酶(SOD)总活力比对照组明显降低(P＜0.01);丙二醛(MDA)含量比对照组明显升高(P＜0.01);ALI+N-LIP组T-SOD降低、MDA升高的程度均明显小于ALI组(P＜0.05)。4.SP-A免疫组织化学显示:ALI组肺组织中SP-A含量较对照组明显降低;ALI+N-LIP组的SP-A的含量比对照组、AIL组明显增多。5.肺部HE染色显示ALI组、ALI+N-LIP组均有不同程度的肺损伤,即有肺组织毛细血管出血,肺泡间隔增宽,肺泡融合,肺泡腔内出现炎性细胞浸润。但ALI+N-LIP组损伤程度明显轻于ALI组。结论:非创伤性肢体缺血预处理对脂多糖诱导的急性肺损伤有保护作用,其作用机制可能与促进SP-A表达和抗氧化作用有关。更多还原

【Abstract】 Objectives: In order to observe the protective effect of noninvasive limb ischemic preconditioning on acute lung injury induced by lipopolysaccharide (LPS) of rats, the changes of lung function, white blood cells(WBC) and lactate dehydrogenase (LDH) in bronchoalveolar lavage fluid (BALF), serum superoxide dismutase(SOD) and malondialdehyd(MDA) have been tested, and the content of pulmonary surfactant-associated protein-A(SP-A) and pathological change of pulmonary tissue were also compared with control following animal model.Methods: Fifteen female SD rats were divided randomly into Control Group, Acute lung injury Group (ALI Group),Acute lung injury and noninvasive limb ischemic preconditioning Group (ALI+N-LIP Group). Pentobarbital sodium was used to anesthetize by intraperitoneal injection. Both lower extremities in ALI+N-LIP Group were bind with tourniquet for 5 minutes every time. The tourniquet was released for 5 minutes. The preconditioning was repeated for 3 times. After it, ALI models were established by LPS in intraperitoneal injection in ALI Group and ALI+N-LIP Group .The normal saline (NS) in tales doses was injected in Control Group. One hour later, all rats were separately stimulated by methacholine (Mch) in four doses (0.39ng/mL、0.78ng/mL、 1.56ng/mL、3.12ng/mL)in order. The airway resistance (AR) and dynamic compliance (Cdyn) were recorded by Buxco. Blood samples and BALF were collected, the amounts of WBC in BALF were counted by cytometry and the level of LDH in BALE was also tested by automatic biochemistry analyzer. The level of seram MDA and SOD were examined by chromatometry. The lung tissues were acquired to observe the content of pulmonary surfactant-associated protein-A (SP-A) by immunohisto- chemistry and pathological changes by HE.Results: 1. Compared with Control Group, AR in ALI Group was significantly increased (P<0.01) and Cdyn was decreased (P<0.01) after stimulus by Mch. The increasing rate of AR and decreasing rate of Cdyn in ALI+N-LIP Group were less than in ALI Group.2. Compared with Control Group, the level of WBC and LDH in BALF for ALI Group and ALI+N-LIP Group were higher(P<0.01). Those in ALI+N-LIP Group were much lower than ALI Group (P<0.05).3. Compared with Control Group, in ALI Group, the total activity of SOD was weaker (P<0.01) and the level of MDA was higher (P<0.01). In ALI+N-LIP Group, the total activity of SOD was higher and the level of MDA was lower than ALI Group.4. The content of SP-A in ALI+N-LIP Group was strongest in three groups (P<0.01), while that in ALI Group was weakest (P<0.01).5. Acute lung injury in different extend could be observed both in ALI Group and ALI+N-LIP Group. The pathological phenomenons were capillary hemorrhage, alveolar septum widened, fusion of pulmonary alveoli and inflammatory cell infiltrate. But the degree of injury in ALI+N-LIP Group was less than ALI Group.Conclusion: noninvasive limb ischemic preconditioning has protective effect on acute lung injury induced by LPS in rats. Their possible mechanisms are related to by improving the secretion of SP-A and antioxidation.更多还原