肾上腺髓质素对内皮素心肌损伤的保护

PROTECTIVE EFFECT OF ADRENOMEDULLIN ON ENDOTHELIN-INDUCED MYOCARDIAL INJURY

本实验在离体灌流大鼠心脏模型上观察了肾上腺髓质素（ＡＭ）和内皮素的相互作用。发现应用内皮素（１０－９ｍｏｌ／Ｌ）灌流可引起冠脉严重痉挛、心脏功能和组织损伤。ＡＭ（１０－８，１０－７ｍｏｌ／Ｌ）与内皮素同时灌流能有效地减轻内皮素所引起的心脏损伤，显著）曾加冠脉流量和ＬＶ±ｄｐ／ｄｔｍａｘ，抑制心室内压急剧升高和心肌脂质过氧化物形成，减少细胞内酶（ＬＤＨ）漏出、心肌ＭＤＡ释放和心肌钙含量的增高。ＡＭ的保护作用是剂量依赖的。提示，作为内源性内皮素拮抗剂，ＡＭ对防治心肌缺血损伤有临床意义。

The interaction between adrenomedullin and endothelin were studied on the isolated perfused rat heart.It was found that perfusion with endothelin(10-9mol/L) exerted severe vasoconstrictor effect on coronary artery and damage effect on myocardium. However . when adrenomedullin(10-9,1 0-7mol/L)was added together with endothelin to the perfusion fluid, it effectively alleviated endothelin-induced damage of the heart,significantly elevated coronary perfusion flow and amplitude of LV±dp/dt max,markedly inhibited the increase of intraventricular pressure (LVPSP,LVPDP)and formation of myocardial lipid peroxidation,and obviously reduced leakage of intracellular enzyme(lactate dehydrogenase LDH) ,release of myocardial MDA and gain of myocardium calcium.The cardioprotective action of adrenomedullin was in a dose-dependent manner. These dates suggest that adrenomedullin as an endogenous antagonist of endothelin or cardioprotector ,may be used for myocardial ischemic injury in the clinics.