目的 观察血管紧张素(1-7)[Ang-(1-7)]对压力负荷增高所致大鼠心肌重构的影响.方法 30只雄性SD大鼠随机分为3组:假手术组、腹主动脉缩窄(AAC)组和Ang-(1-7)组.后2组采用腹主动脉缩窄术建立心脏压力负荷增高动物模型.术后1 d开始,Ang-(1-7)组大鼠经渗透性微量泵持续颈静脉输注Ang(1-7)25 μg·kg-1·h-1,假手术组及AAC组经渗透性微量泵给予等量生理盐水.4周后鼠尾容积法测量收缩压;称取左心室质量(LVM),计算左心室质量指数(LVMI);HE染色检测心肌细胞平均直径;放免法测定血浆和心肌血管紧张素II(Ang II)浓度.结果 与假手术组相比,AAC组、Ang-(1-7)组收缩压、LVM、LVMI、心肌Ang II浓度、心肌细胞平均直径均显著升高(P<0.05,P<0.01).与AAC组相比,Ang-(1-7)组血压和心肌Ang II浓度差异无统计学意义(P﹥0.05),但LVM、LVMI、心肌细胞平均直径明显降低(均P<0.05).结论 Ang-(1-7)可改善腹主动脉缩窄高血压大鼠左室肥厚,逆转心肌重构.%Objective To investigate the effect of angiotensin ( 1 -7 )on myocardial remodeling which induced by pressure overload in rats. Methods Thirty SD rat were randomly divided into 3 groups. Left ventricular hypertrophy was induced by abdominal aortic constriction ( AAC ) and received angiotensin ( 1-7 ) ( 25 μg · kg-1· h-1 )( n = 10 ). Sham operated rats ( n = 10 ) and untreated AAC rats ( n = 10 ) served as controls. Systolic blood pressure ( SBP ) and LVMI were determined, cardiomyocytes diameter were measured by HE stain; plasma angiotensin II and myocardial angiotensin II levels was detected by radioimmunoassay. Results Compared with sham operation group, SBP, LVMI, mean diameter of cardiomyocytes and myocardial angiotensin II concentration in AAC rats were significantly increased ( P < 0.05, P <0. 01 ). SBP and myocardial angiotensin II concentration had no significant differences between AAC rats and Ang ( 1-7 ) rats( P > 0. 05 ), while LVMI, mean diameter of cardiomyocytes in Ang ( 1-7 ) rats were significantly decreased ( all P < 0. 05 ). Conclusion Ang ( 1-7 ) could prevent the development of myocardial hypertrophy in pressure overloaded rats and reverse myocardial remodeling.
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