巯甲丙脯酸防治心肌肥厚对血液动力学和心肌肌球蛋白重链基因表达的影响

Effect of Captopril for Preventing and Treating Myocardial Hypertrophy on Hemodynamics and Cardiac Myosin Heavy Chain Genes Expression in Rats

目的 :研究巯甲丙脯酸 (captopril)在防治心肌肥厚过程中 ,对大鼠血液动力学和心肌肌球蛋白重链 (MHC)基因表达的影响。 方法 :将 6 0只大鼠随机分 3组即 :对照组 (n=17)、心肌肥厚组 (n=19)、心肌肥厚 +巯甲丙脯酸组 (n=2 4) ,观察巯甲丙脯酸对主动脉缩窄大鼠血浆和心肌血管紧张素 (Ang )含量、血液动力学以及左心室心肌α- MHC和β- MHC基因表达的作用。 结果 :1心肌肥厚组大鼠全心重 /体重值及心肌 Ang 含量较对照组明显增加 ;收缩压、平均动脉压、左心室收缩压、左心室等容收缩期压力变化速率最大值 (+dp/ dtmax)显著升高 ;α- MHC基因表达减弱 ,β- MHC基因表达增强。 2巯甲丙脯酸组大鼠的全心重 /体重值及心肌 Ang 的含量显著低于心肌肥厚组 ;使舒张压和平均动脉压显著降低 ;使心肌α- MHC基因表达增强 ,β- MHC基因表达减弱。 结论 :巯甲丙脯酸通过抑制 Ang 的生成 ,逆转压力超负荷所致的心肌 MHC表型的转化 ,有效地防治了心肌肥厚的发生 ,改善了心脏功能。

Objective:To investigate the effect of captopril,an angiotensin converting enzyme inhibitor,on hemodynamics and cardiac myosin heavy chain (MHC)genes expression during prevention and treatment of myocardial hypertrophy. Methods:The angiotensin Ⅱ both in plasma and in the left ventricular tissue of Sprague Dawley rats were tested by radioimmunoassay.Hemodynamics was determined by cardiac function test methods.α MHC messenger ribonucleic acid(mRNA) and β MHC mRNA expression of the ventrucular tissue were analyzed by Dot blot method. Results:①Cardiac hypertrophy developed obviously 6 weeks after the constriction of abdominal aorta.The increase in the ratio of heart weight/body weight(HW/BW) and the content of myocardium angiotensin Ⅱ,the rise in SBP,MAP,LVSP,+dp/dt max were shown.The amount of α MHC mRNA expression decreased,while that of β MHC mRNA expression increased.②Treating with captopril,the ratio of HW/BW,the content of myocardium angiotensin Ⅱ,and the level of DBP、MAP were significantly reduced.The decrease in α MHC mRNA expression and the increase in β MHC mRNA expression were partly reversed.The ratio of α MHC mRNA/β MHC mRNA was raised. Conclusion:Captopril may effectively prevent and treat hypertrophy,regulate cardiac MHC isoform expression and improve cardiac function.