L－精氨酸二肽对大鼠异丙肾上腺素心肌损伤的影响

在大鼠异丙肾上腺素（ＩＳＯ）心肌坏死模型上发现心肌环─磷酸鸟苷（＿ｃＧＭＰ）含量明显减少，冠脉流量降低，冠血管对乙酰胆碱（Ａｃｈ）扩血管反应（内皮依赖性）减弱，而对硝普钠（ＮＰＳ）的扩血管反应（非内皮依赖性）无明显改变。用内皮衍生松驰因子（ＥＤＲＦ）前体Ｌ－精氨酸二肽（Ｌ－Ａｒｇ－Ａｒｇ－ＯＨ）治疗可明显减轻ＩＳＯ心肌损伤，增加心肌＿ｃＧＭＰ含量，增加冠脉灌流量，改善冠血管对Ａｃｈ的舒张反应。实验结果表明，ＩＳＯ心肌坏死时冠脉内皮ＥＤＲＰ生成减少，应用Ｌ－精氨酸二肽具有防治意义。

Effect of L-arginine dipeptide on isoprenaline-induced myocardial injury in rats

This work was performed on rat myocardial necrosis produced by percut-anous in jection of isoprenaline.It was found that myocardial cGMP content and coronaryperfusion flow were significantly decreased,and endothelium dependent vasodilation of thecoronary vessels to acethlcholine(Ach)was weakened,however, endothelium-independentvasodilation to sodium nitroprusside was not changed.Treatment with the precursor ofendothelium-derived relaxing factor(EDRF)-L-arginine dipeptide(L-Arg Arg-OH)protectedthe heart against isoprenaline injury elevated myocardial cGMP content, enhanced coronaryperfusion flow,and improved vasodilation response of coronary vessels to Ach.Theseresults suggested that the production of EDRF was lowered during isoprenalin-inducedmyocardial necrosis, and that L-arginine dipeptide could have preventive and therepeuticvalue for myocardial ischemia and necrosis.