压力超负荷性心肌肥厚大鼠心肌ADM与ET变化的实验研究

目的:探讨心肌肾上腺髓质素(ADM)在大鼠压力超负荷性心肌肥厚中的病理生理意义及与内皮素(ET)的关系。方法:20只Wistar大鼠随机分为假手术组和腹主动脉部分缩窄致心肌肥厚组。6周后观察尾动脉收缩压(SBP),左心系数(左心室重/体重LVW/BW)的变化,采用放免分析法检测心肌ADM和ET水平。结果:心肌肥厚组与假手术组比较,SBP、LVW/BW分别增加161.7%和119.3%(P<0.01),心肌ADM、ET及ET/ADM值分别增加172.1%、246.1%、143.4%(P<0.01),ADM、ET、ET/ADM值与LVW/BW呈正相关,ADM与ET呈正相关。结论:在此心肌肥厚模型中心肌肾上腺髓质素升高,可能是作为心肌自分泌和/或旁分泌激素在组织局部起抗心肌肥厚的作用。心肌肥厚时ET、ADM间的动态平衡被打破,其调节紊乱可能是发病的重要原因之一。

Changes of Adrenomedullin and Endothelin in Pressure Overload Rats with Myocardial Hypertrophy

Objective:To investigate the pathophysiological role of cardiac adrenomedullin(ADM) and its relationship with endothelin(ET) in pressure overload rats with myocardial hypertrophy.Methods:20 Wistar rats were randomly divided into two groups:sham-operated group and myocardial hypertrophy group induced by partial abdominal arota constriction.The changes of systolic blood pressure(SBP) of caudal artery and left ventricular mess index(left ventricular weight versus body weight,LVW/BW) were observed after 6 weeks and the levels of myocardial ADM and ET were determined by radioimmunoassay method.Results:Compared with shame-operated group,SBP and left ventricular mess index in myocardial hypertrophy group increased by 161.7% and 119.3%(P<0.01),and the levels of ADM,ET and the ratio of ET/ADM in myocardium increased by 172.1%,246.1% and 143.4%,respectively(P<0.01).There was positive correlation between ADM,ET,ET/ADM and LVW/BW,or ADM and ET.Conclusion:The increasing ADM may play a negative role in myocardial hypertrophy.The disbalance between ET and ADM occurs in myocardial hypertrophy,which may be one of important etiological factors.