体外循环对大鼠肠黏膜屏障功能的影响

目的　观察大鼠体外循环(CPB)围术期肠黏膜通透性的变化以及对肠黏膜屏障功能的影响。方法　建立大鼠CPB模型,按照CPB后不同时间进行分组,分别采血测定血浆D-乳酸和脂多糖(LPS)的浓度并观察小肠组织病理变化。结果　CPB 1h后血浆D-乳酸和LPS开始升高,CPB结束后1h达到峰值,CPB后8h恢复正常。二者变化趋势一致,呈正相关(r=0. 8312 ,P <0 .0 5 ) ;CPB后小肠绒毛顶端上皮脱落,固有层白细胞聚集。结论　CPB术后早期肠黏膜屏障功能就已经受到损害,通透性增加。血浆D 乳酸浓度变化可用来判断肠黏膜屏障损伤程度,为CPB严重并发症的防治和预后评估提供有益的参考和实验依据

Effect of cardiopulmonary bypass on the gut mucosal barrier function in rat model

Objective To investigate the change of intestine mucosal permeability during cardiopulmonary bypass (CPB) and its effect on gut barrier in rats model. Methods The rats model of CPB was established and samples of tissue and plasma were collected at different intervals. Plasma D-lactate and LPS concentrations were determined and gut tissue was examined microscopically. Results The plasma concentration of D-lactate and LPS increased gradually at 1h CPB, and increased markedly 1h after CPB. They recovered to normal 8h after CPB, respectively. In addition, it was noted that there was a significant positive correlation between the plasma concentrations of LPS and D-lactate (r = 0.8312, P<0.05). Desquarnation of intestine villi and infiltration of inflammatory cells in the lamina propria were observed 1h after CPB. Conclusion The results suggested that the gut mucosal barrier was impaired during early stage of CPB, which resulted in increased mucosal permeability, intestine derived endotoxemia, and organ dysfunction. It was found that plasma D-lactate can reflect the degree of gut barrier injury, which contributes to judging the course of disease and preventing the complications after CPB.