摘要目的 评价体外循环(CPB)对大鼠肺组织紧密连接蛋白occludin表达的影响.方法 健康清洁级雄性SD大鼠20只,4～6月龄,体重330 ～ 400 g,采用随机数字表法,将大鼠随机分为2组(n=10):假手术组(S组)和CPB组,CPB组行CPB 1 h,观察2h.于CPB结束后2h时,测定肺组织含水量、支气管肺泡灌洗液(BALF)蛋白浓度和中性粒细胞百分比,免疫组织化学和Western blot法检测肺组织occludin表达,透射电镜下观察肺泡上皮屏障超微结构.结果 与S组比较,CPB组肺组织含水量、BALF蛋白浓度及中性粒细胞百分比升高,肺组织occludin表达下调(P＜0.05),肺泡上皮屏障损伤加重.结论 CPB后大鼠肺组织occludin表达下调,肺泡上皮屏障损伤,可能是CPB诱发急性肺损伤的重要因素之一.

abstractsObjective To investigate the effects of cardiopulmonary bypass (CPB) on the expression of tight junction protein occludin in rat lung tissues.Methods Twenty adult male Sprague-Dawley rats were randomly divided into 2 groups (n=10 each): sham operation group (group S) and CPBgroup.The rats underwent 1 h of CPB and were observed 2 h later in group CPB.The lung water content,neutrophil percentage and protein concentration in bronchoalveolar lavage fluid (BALF) were measured.The expression of occludin in lung tissues was detected by immunohistochemistry and Western-blot analysis.The ultrastructure of alveolar epithelial barrier was observed with transmission electron microscope.Results Compared with group S,the lung water content,protein concentration in BALF and neutrophil percentage were significantly increased (P ＜ 0.05),the expression of occludin in lung tissues was significantly down-regulated (P ＜ 0.05) and the damage to alveolar epithelial barrier was aggravated in group CPB.Conclusion The expression of occludin in lung tissues is down-regulated and the damage to alveolar epithelial barrier is induced after CPB,which may be one of the important factors in acute lung injury induced by CPB.