葡萄籽原花青素提取物对心肌梗死大鼠肾素-血管紧张素系统及AQP2蛋白表达的影响

Effect of Grape Seed Proanthocyanidin Extract on Renin-angiotensin System and AQP2 Protein Expression in Rats with Myocardial Infarction

目的:探讨葡萄籽原花青素提取物(GSPE)对心肌梗死大鼠肾素血管紧张素-系统及水通道蛋白2(AQP2)表达的影响。方法:将55只无特定病原体(SPF)级Sprague-Dawley(SD)大鼠按照随机数字表法分为健康组、模型组、辛伐他汀组、GSPE低剂量组及GSPE高剂量组,每组11只。除健康组外其余大鼠均采用冠状动脉结扎法制备心肌梗死模型,建模成功后,GSPE低剂量组、高剂量组大鼠分别灌胃100 mg/kg、400 mg/kg葡萄籽原花青素溶液,辛伐他汀组灌胃40 mg辛伐他汀溶液。苏木精-伊红(HE)染色后观察心肌组织形态;末端脱氧核苷酸转移酶介导的原位缺口末端转移酶标记法(TUNEL)检测心肌细胞凋亡;超声心动图监测心功能;放射免疫法检测血管紧张素Ⅱ(AngⅡ)、血浆肾素活性(PRA)、醛固酮水平;免疫印迹法检测心肌组织中AQP2、B细胞淋巴瘤/白血病2号基因(Bcl-2)及半胱天冬氨酸蛋白酶-3(Caspase-3)蛋白水平。结果:与健康组比较,模型组大鼠左心室收缩末期内径(LVESD)、左心室舒张末期内径(LVEDD)升高,左心室射血分数(LVEF)和左心室短轴缩短分数(LVFS)降低(P<0.05);与模型组比较,GSPE低剂量组、GSPE高剂量组及辛伐他汀组LVEDD、LVESD降低,LVEF、LVFS升高(P<0.05),GSPE低剂量组、GSPE高剂量组间比较差异有统计学意义,而GSPE高剂量组与辛伐他汀组比较差异无统计学意义(P>0.05)。与健康组比较,模型组大鼠AngⅡ、PRA、醛固酮升高(P<0.05);与模型组比较,GSPE低剂量组、GSPE高剂量组及辛伐他汀组AngⅡ、PRA、醛固酮降低(P<0.05)。健康组、模型组、GSPE低剂量组、GSPE高剂量组及辛伐他汀组的心肌细胞凋亡率分别为(5.11±0.33)%、(46.22±3.97)%、(28.46±3.77)%、(15.42±2.33)%及(16.34±2.57)%,各组比较差异有统计学意义(P<0.05)。与健康组比较,模型组大鼠心肌组织中AQP2、Caspase-3蛋白水平升高,Bcl-2蛋白水平降低(P<0.05);与模型组比较,GSPE低剂量组、GSPE高剂量组、辛代他汀组大鼠心肌组织中AQP2、Caspase-3蛋白水平降低,Bcl-2蛋白水平升高(P<0.05)。结论:GSPE对心肌梗死有保护作用,可改善心功能水平,减少心肌细胞凋亡,其作用机制可能与调控AQP2蛋白表达有关。

Objective:To study the effect of grape seed proanthocyanidin extract(GSPE)on the renin-angiotensin system and aquaporin-2(AQP2)protein expression in myocardial infarction(MI)rats.Methods:Fifty-five specific pathogen free(SPF)Sprague-Dawley rats were randomly divided into healthy group,model group,simvastatin group,low-dose GSPE group,and high-dose GSPE group,with 11 rats in each group.Except for the healthy group,the other rats were prepared by coronary artery ligation to establish the MI model.After successful modeling.the rats in low-and high-dose GSPE groups were orally administered with GSPE solution at doses of 100 mg/kg and 400 mg/kg,respectively.The rats in simvastatin group were orally administered with 40 mg simvastatin solution.Hematoxylin-eosin(HE)staining was used to observe the morphology of myocardial tissue.Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL)assay was used to detect myocardial cell apoptosis.Echocardiography was used to monitor cardiac function.Radioimmunoassay was used to detect angiotensinⅡ(AngⅡ),plasma renin activity(PRA),and aldosterone levels.Immunoblotting was used to detect the protein levels of AQP2,B-cell lymphoma/leukemia-2(Bcl-2),and Caspase-3 in my ocardial tissue.Results:Compared with the healthy group,the left ventricular end-diastolic diameter(LVEDD)and left ventricular end-systolic diameter(LVESD)of rats in model group increased,while the ejection fraction(LVEF)and fr actional shortening(LVFS)decreased(P<0.05).Compared with model group,LVEDD and LVESD in low-and high-dose GSPE groups and simvastatin group decreased,while LVEF and LVFS increased(P<0.05).There were differences between low-and high-dose GSPE groups,but no significant difference between high-dose GSPE group and simvastatin group(P>0.05).Compared with healthy group,the levels of AngⅡ,PRA,and aldosterone in model group increased(P<0.05).Compared with model group,the levels of AngⅡ,PRA,and aldosterone in low-and high-dose GSPE groups and simvastatin group decreased(P<0.05).The apoptosis rates of myocardial cells in healthy group,model group,low-dose GSPE group,high-dose GSPE group,and simvastatin group were(5.11±0.33)%,(46.22±3.97)%,(28.46±3.77)%,(15.42±2.33)%,and(16.34±2.57)%,respectively,with statistically significant differences between the groups(P<0.05).Compared with healthy group,the levels of AQP2 and Caspase-3 proteins in myocardial tissue of rats in model group increased,while the level of Bcl-2 protein decreased(P<0.05).Compared with model group,the levels of AQP2 and Caspase-3 proteins in myocardial tissue of rats in low-dose GSPE group,high-dose GSPE group,and simvastatin group decreased,while the level of Bcl-2 protein increased(P<0.05).Conclusion:GSPE shows a protective effect on MI,which can improve cardiac function,reduce myocardial cell apoptosis,and its mechanism may be related to the regulation of AQP2 protein expression.