Effects of cardiopulmonary bypass on expression of tight junction protein occludin in rat lung tissues / 中华麻醉学杂志

ABSTRACT

Objective 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.