C型利钠利尿肽对犬冠脉循环的作用

Ｃ型利钠利尿肽（ＣＮＰ）是新近发现的一种由内皮细胞分泌的利钠利尿肽，本研究采用冠脉内给药方法对比观察了ＣＮＰ、心房利钠尿肽（ＡＮＰ）对犬正常及心肌缺血后冠脉循环的作用，并应用常规离体血管灌流的方法测定了离体冠脉对ＣＮＰ、ＡＮＰ的舒张反应。结果显示：（１）对正常犬，ＣＮＰ、ＡＮＰ均可降低平均动脉压（ＭＡＰ）、远端小冠脉压和大、小冠脉阻力，增加冠脉流量，而不影响心率；（２）心肌缺血后，ＣＮＰ的上述作用依然存在，但ＡＮＰ降低ＭＡＰ的作用基本消失。（３）离体心外膜冠状动脉对ＣＮＰ、ＡＮＰ均呈剂量依赖性舒张反应。结果提示ＣＮＰ、ＡＮＰ均可舒张冠状动脉而改善冠脉循环，并可能对急性心肌缺血的治疗有益

EFFECTS OF C TYPE NATRIURETIC PEPTIDE ON CANINE CORONARY CIRCULATION

In the present study, the effects of C type natriuretic peptide(CNP)and atrial natriuretic peptide (ANP) on canine coronary circulation after intracoronary injection and their vasorelaxant effects upon canine epicardial coronary artery by in vitro perfusion were comparativiely investigated. The results indicated that, in addition to eliciting concentration dependent relaxation of canine epicardial artery,both ANP and CNP could significantly increase coronary blood flow (CBF),with decreased parameters such as coronary artery resistance, mean aortic pressure (MAP) and distal coronary arterial pressure(DCP) of normal dogs. Aftet myocardial ischemia, both CNP and ANP had similar effect upon canine coronary circulation, but MAP was not significantly influenced by ANF. These results suggest that CNP and ANP can improve the canine coronary circulation via relaxing the coronary artery and thus they might be benificial to the treatment of acute myocardial ischemia.