降钙素基因相关肽和心房肽对心肌缺血犬冠脉循环及离体冠脉的影响

The effects of CGRP and ANP on canine coronary circulation and in vitro canine coronary artery after myocardial ischemia

本实验利用冠脉内给药和离体血管灌流等方法，观察并比较了降钙素基因相关肽（ＣＧＲＰ）和心房肽（ＡＮＰ）对犬冠脉循环的影响及心肌缺血后冠脉对二者反应性的变化。结果表明，冠脉内注射ＣＧＲＰ或ＡＮＰ均能明显逆转急性心肌缺血所致冠脉血流量的显著减少和大小冠脉阻力的显著增加，其中对远端小冠脉阻力降低的程度明显大于犬冠脉，而且ＣＧＲＰ的上述作用显著强于ＡＮＰ。ＣＧＲＰ和ＡＮＰ均可呈剂量依赖性舒张正常及心肌缺血后的大、小冠脉血管；二者对大冠脉的舒张作用显著弱于小冠脉，而ＣＧＲＰ的舒血管效应又强于ＡＮＰ。心肌缺血后大冠脉对ＣＧＲＰ和ＡＮＰ反应性显著降低，而小冠脉无此现象。结果提示，ＣＧＲＰ是一种强有力的内源性扩血管物质，对缺血性心脏病的治疗有益。

In present study ,the effects of calcitonin gene─related peptide(CGRP)andartrial natduatic peptide(ANP)on canine coronary circulation after intracoronaty injectionfollowing myocardial ischemia and changes of response of epicardial proximal coronaryartery(PCA)and distal coronary artery(DCA)were observed and compared to them byin vitro pejrfusion.The results indicated that both CGRP and ANP could reverse de-creased coronary blood flow and increased resistance of PCA and DCA induced bymyocardial ischemia,and the resistance decrease of DCA was much larger than that that of PCA.The above effects of CGRP were stronger than those of ANP.Both CGRP andANP elicited dose─dependent relaxing effects on PCA and DCA following normal and myocardial ischemia,and the relaxing effect on PCA was much weaker than that ofDCA,the relaxing effed of CGRP were stronger than those of ANP. The response ofPCA to CGRP and ANP was decreasing obviously after myocardial ischemia in vivo,butneither was DCA. These results suggestal that CGRP is a more potent endogenous vasodilator,and benificial to the tretment of ischemic heart disease.