体外循环后羊心肌组织中水通道蛋白1表达及其与心肌水肿的关系

Expression of aquaporin 1 in myocardial tissues of sheep after cardiopulmonary bypass and its relationship with myocardial edema

目的探讨体外循环后羊心肌组织中水通道蛋白1(AQP1)的表达及其与心肌水肿的关系。方法健康成年羊24只,随机分为正常对照组(n=6)和体外循环组(n=18),体外循环组在体外循环结束后6个时点(2、6、12、24、48、72 h)取材,每个时点取3只动物。采用Real-Time PCR、Western blotting、ELISA和干湿质量法检测正常对照组术后和体外循环组术后各时点心室肌组织中AQP1表达及心肌水肿的程度。结果正常羊心室肌组织中有AQP1表达,且左、右心室心肌组织的表达差异无统计学意义(P>0.05)。体外循环组在体外循环结束后各时点间心肌组织中AQP1表达差异均有统计学意义(P<0.05),表达趋势在mRNA和蛋白水平一致,均为体外循环结束后开始降低,6 h后达到最低,而后上升,于48 h达到峰值后再降低;心肌水肿程度各时点间差异也均有统计学意义(P<0.05),变化趋势随着体外循环后时间的推移逐渐增高,于48 h达到峰值后降低;AQP1 mRNA相对表达量与AQP1蛋白相对表达量之间存在正相关(r=0.971,P<0.05),AQP1蛋白相对表达量与心肌水含量呈正相关(r=0.592,P<0.05)。结论体外循环可影响羊心肌组织中AQP1表达及心肌水肿变化,且AQP1蛋白表达量与心肌水含量呈正相关。

Objective To investigate the expression of aquaporin 1（AQP1） in myocardial tissues of sheep after cardiopulmonary bypass and its relationship with myocardial edema. Methods Twenty-four healthy adult sheep were randomly divided into normal control group（n=6） and cardiopulmonary bypass group（n=18）,and animal samples were obtained at 6 time points（2 h,6 h,12 h,24 h,48 h and 72 h） after cardiopulmonary bypass in cardiopulmonary group,with 3 sheep at each time point.Real-Time PCR,Western blotting,ELISA and dry/wet method were employed to determine the expression of AQP1 in myocardial tissues of ventricles and severity of myocardial edema at different time points after cardiopulmonary bypass in two groups. Results There existed expression of AQP1 in myocardial tissues of ventricles of sheep in normal control group,and there was no significant difference between myocardial tissues of left ventricles and those of right ventricles（P0.05）.In cardiopulmonary bypass group,there were significant differences in the expression of AQP1 in myocardial tissues among different time points after cardiopulmonary bypass（P0.05）,and the expression tendency of AQP1 mRNA was in line with that of AQP1 protein.The expression of AQP1 mRNA and AQP1 protein in cardiopulmonary bypass group began to decrease after cardiopulmonary bypass,reached the minimum level 6 h after cardiopulmonary bypass,increased from then on,reached the peak level 48 h after cardiopulmonary bypass,and decreased after that time point.There were significant differences in the severity of myocardial edema among different time points after cardiopulmonary bypass（P0.05）.The severity of myocardial edema began to increase after cardiopulmonary bypass,reach the peak level 48 h after cardiopulmonary bypass,and began to decrease after that time point.The relative expression of AQP1 mRNA was positively related to that of AQP1 protein（r=0.971,P0.05）,and AQP1 protein was positively related to the water content in myocardium（r=0.592,P0.05）. Conclusion Cardiopulmonary bypass may influence the expression of AQP1 and severity of myocardial edema in sheep,and there is positive relationship between AQP1 protein and myocardial edema.