DADLE对大鼠急性全脑缺血再灌注继发肺损伤的作用

Effect of DADLE on lung injury in rats with acute global cerebral ischemia-reperfusion

目的:通过建立大鼠急性全脑缺血再灌注模型,观察肺组织超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量及肺组织光镜、电镜病理变化,探讨δ阿片受体激动剂DADLE对急性肺损伤的保护作用。方法:SD大鼠30只随机分为假手术(sham)组、模型(I/R)组和DADLE处理组。采用改良的二血管阻断加低血压法建立全脑缺血再灌注模型。DADLE处理组(n=10)于再灌注前经左侧颈静脉注射DADLE 5 mg/kg,再灌注120 min后,取肺组织,光镜、电镜观察其病理学改变及检测肺组织SOD活性、MDA含量。右侧股动脉取血测定氧分压,计算氧合指数。结果:I/R组与sham组比较,肺脏表现为肺泡间隔增宽,毛细血管扩张充血,肺胞腔内及血管周围中性粒细胞浸润,Ⅱ型上皮细胞表面微绒毛明显减少,肺胞腔及气管腔均有浆液渗出,大鼠肺组织SOD活性降低和MDA含量升高。DADLE处理组与I/R组比较肺脏充血减轻,肺组织损伤程度明显减轻,中性粒细胞浸润有所减少,SOD活性升高和MDA含量降低。DADLE处理组动脉血氧分压和氧合指数有升高趋势,与I/R组比较差异有统计学意义。结论:大鼠急性全脑缺血再灌注模型对肺有不同程度的损伤,DADLE可减轻急性肺损伤,对肺组织提供一定的保护作用。

AIM： To observe the effects of δ opioid receptor agonist DADLE on acute lung injury（ ALI） induced by acute global cerebral ischemia-reperfusion in rats. METHODS： SD rats（ n = 30） were randomly divided into sham group,model（ I /R） group and DADLE treatment group. Global cerebral ischemia-reperfusion model was established by a modified 2-vessel occlusion plus hypotension. DADLE（ 5 mg /kg） treatment was performed via the left jugular injection before reperfusion. After 120-min reperfusion,the pathological changes of the lung tissues were observed under light microscope and electronic microscope. The activity of superoxide dismutase（ SOD） and malondialdehyde（ MDA） level were detected. The partial pressure of arterial oxygen（ PaO2） was also measured. RESULTS： In I/R group,widened alveolar septum,capillary dilatation and congestion,endovascular and perivascular cells in the lung with neutrophil infiltration,and significantly reduced type II epithelial cell surface microvilli,alveolar lumen cavity and trachea with serous exudate were observed. SOD activity decreased,but the MDA level increased. Compared with I /R group,the SOD activity increased and MDA level decreased in DADLE treatment group,with significantly reduced lung congestion,the degree of lung injury,and the infiltration of neutrophils. Compared with I /R group,the PaO2 and oxygenation index in DADLE treatment group were increased. CONCLUSION： Various degrees of pulmonary injury were observed in acute global cerebral ischemia reperfusion model. DADLE might have a protective effect on lung tissues of ALI in rats.