肾上腺髓质素对离体灌流大鼠心脏缺血—再灌注损伤的保护作用

PROTECTIVE EFFECT OF ADRENOMEDULLIN ON ISCHEMIA-REPERFUSION INJURY IN THE ISOLATED PERFUSED RAT HEART

肾上腺髓质素（ＡｄｒｅｎｏｍｅｄｕｌｌｉｎＡＭ）是从人肾上腺嗜铬细胞中分离的一种降压多肽。本工作利用离体灌流的大鼠心脏模型，观察了ＡＭ的心脏保护效应。再灌注时应用ＡＭ（１０￣（－７）ｍｏｌ／Ｌ）治疗明显提高心肌对缺氧的耐受性，减轻再灌注损伤。冠脉流量恢复到正常水平，而心肌蛋白、ＬＤＨ漏出，心肌脂质过氧化形成和心肌钙含量的升高分别被抑制。结果表明，ＡＭ作为内源性抗损伤物质可以有效地防治心肌缺血──再灌注损伤。

Adrenomedullin (AM)is a recently discovered novel hypotensive peptide which is isolated from human pheochromocyte.The cardioprotective effect of human adrenomedullin on ischemia-reperfusion injury were investigated in the isolated perfused rat heart to clarify its physiological and pathophysiological implications.It was found that reperfusion with human adrenomedullin (10^(-7)mol /L )significantly strengthened the resistant capacity of myocardium to anoxia,and alleviated myocardial anoxia-reoxygenation damage.The coronary perfusion flow returned to the normal level,and the leakage of protein and LDH,formation of myocardial lipid peroxidation and elevation of myocardium calcium content were inhibited respectively.These results suggest that adrenomedullin as an endogenous anti-injury substance is more effective for the prevention and therapy of myocardial ischemia-reperfusion injury.