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目的 探讨急性肺损伤时肺组织及外周血中性粒细胞 (PMN)凋亡和坏死的发生规律及其与肺损伤的关系 ,以及可能涉及的机制。方法 Wistar大鼠 5 0只 ,腹腔注射脂多糖 (LPS ,O55B5,3mg/kg)造成大鼠急性肺损伤 ,分为LPS注射后 2h组、4h组、8h组、12h组及正常对照组。于预定时相取血及支气管灌洗液 ,密度梯度离心分离PMN ,用流式细胞仪测定凋亡、坏死细胞比例及呼吸爆发功能 ,同时测定乳酸脱氢酶 (LDH)含量、肺通透指数、肿瘤坏死因子 (TNF)、白细胞介素 (IL) 1β、IL 6含量和Ca2 + 浓度。结果 ALI大鼠肺灌洗液中PMN凋亡、坏死比例的变化与外周血不同 ,主要表现为存活细胞比例增加 ,凋亡延迟。肺灌洗液中TNF、IL 1β、IL 6含量明显高于外周血 ,且持续时间较长 ;同时 ,肺灌洗液LDH明显升高 ,肺通透指数显著增加。结论 肺组织中高浓度的细胞因子和短暂升高的Ca2 + 使游出的PMN的正常凋亡途径发生障碍 ,造成PMN持续处于激活状态及毒性内容物的持续释放 ,与肺组织损伤有密切关系
Objective To investigate the regularity of apoptosis and necrosis of lung and peripheral blood neutrophils (PMN) in acute lung injury and its relationship with lung injury and its possible mechanism. Methods Fifty Wistar rats were injected intraperitoneally with lipopolysaccharide (LPS, O55B5, 3mg / kg) for acute lung injury. They were divided into 2h, 4h, 8h, 12h after LPS injection and normal control group. PMN was isolated from the blood and bronchial lavage fluid at a predetermined time, and density gradient centrifugation was used to detect the apoptosis and necrosis cell ratio and respiratory burst function. The contents of lactate dehydrogenase (LDH), pulmonary permeability index , Tumor necrosis factor (TNF), interleukin (IL) 1β, IL 6 and Ca 2+ concentration. Results The percentage of apoptotic and necrotic PMN in lung lavage fluid of ALI rats was different from that of peripheral blood. The main manifestations were the increase of surviving cells and the delay of apoptosis. Lung lavage fluid TNF, IL 1β, IL 6 levels were significantly higher than peripheral blood, and longer duration; the same time, lung lavage fluid LDH was significantly increased pulmonary permeability index increased significantly. CONCLUSION: High concentrations of cytokines and transiently elevated Ca2 + in lung tissue may impede the normal apoptotic pathway of PMNs, resulting in PMNs being continuously activated and the sustained release of toxic components, which is closely related to lung injury