美托洛尔对充血性心力衰竭大鼠血浆醛固酮浓度、心肌纤维化和心室重构的影响

Effect of Metoprolol on Change of Plasma Aldosterone,Myocardium Fibrosis and Myocardial in Rats with Remodeling Congestive Heart Failure

目的:探讨美托洛尔对充血性心力衰竭(CHF)大鼠血浆醛固酮(ALD)浓度的影响及防治心肌纤维化及心室重构的作用。方法:雄性SD大鼠30只,随机选择20只皮下注射异丙基肾上腺素二次(170mg/kg/次),6周后左室射血分数≤45%确定造模成功;将模型大鼠随机分为模型组(n=10)和美托洛尔治疗组(n=10,8mg/kg/天,共治疗12周);另10只大鼠作为正常对照组。18周后进行心功能指标、血浆ALD浓度检测,并取心肌观察组织形态学及胶原纤维染色。结果:(1)与对照组相比,模型组心功能指标明显恶化,血浆ALD显著升高(P<0.01),心肌纤维化和心室重构明显;(2)与模型组比较,美托洛尔组心功能明显好转,血浆ALD明显下降(P<0.01),心肌纤维化和心室重构明显改善。结论:美托洛尔能通过降低CHF大鼠血浆ALD浓度而改善心功能,逆转心室重塑。

Objective:To investigate the effect of metoprolol on plasma aldosterone,myocardium fibrosis and reverse ventricular remodeling in rats with corgestive heart failure.Method:Male SD rats were randomly allocated to the Isopreternol(ISO)-induced chronic heart failure group(n=20)receiving two subcutaneous injections of 170mg ISO per kilogram of body and the healthy normal group(n=10)receiving two subcutaneous injections of 0.25ml normal saline.At 6th week,the LVEF was measured by echocardiogram,the remaining rats with LVEF≤45% were randomly divided into two groups:control group(n=10),metoprolol group 8 mg/kg/d(n=10).At 18th week,the HR,LVEF,LVEDP,LVSP were assessed.Aldosterone(ALD)in plasma were examined by radio-immunity method,and the mass ratio of heart ventricle and left ventricle to body was measured.Results:(1)Compared with the normal group,the HR,LVEDP and ALD in plasma were significantly increased(P<0.01).But LVSP and ±dp/dtmax were significantly decreased in the control group.(2)Compared with the control group,the HR,LVEDP,LVWI and ALD in plasma were decreased distinctly.The LVSP and ±dp/dtmax were increased distinctly in the metoprolol group(P<0.01).Conclusion:Metoprolol can inhibit ALD in plasma,improve heart function and reverse ventricular remodeling with congestive heart failure.