心钠素对犬冠状动脉循环的调节作用

目的 :探讨生理及病理状态下心钠素调节冠状动脉循环的意义。方法 :应用测量冠状动脉直径的超声波晶体及测冠脉血流的多普勒探针 ,制成动物模型。将犬分别进行如下处理 :单独应用心钠素 ( 2 5、5 0和 1 0 0 ng· kg-1 · min-1 )持续静脉注射 ;HS- 1 4 2 - 1 ( HS)预处理后应用心钠素 ;单独应用 HS,测量冠状动脉直径、冠状动脉血流、平均动脉压、心率、血浆心钠素和环磷酸鸟苷浓度。结果 :单独应用心钠素可扩张冠状动脉直径 ,降低平均动脉压 ,对冠状动脉血流及心率无影响 ,增加血浆心钠素和环磷酸鸟苷浓度 ;HS处理后用心钠素 ,仅增加血浆心钠素浓度 ,其他指标均受抑制 ,单独用 HS对指标无影响。结论 :在以心功能不全为代表的病态下心钠素浓度升高 ,可通过直接扩张血管对维持冠脉循环起重要作用

Regulatory Effect of Atrial Natriuretic Factor on Canine Coronary Circulation

Objective:To investigate the role of atrial natriuretic factor (ANF) in regulating coronary circulation in vivo . Methods: In the paper the effect of intravenous (iv) ANF and/or HS 142 1(HS), a ANF receptor antagonist, in chronically instrumented dogs on circumflex coronary artery diameter (CoD) and coronary blood flow (CBF) were examined. Results:CoD was significantly increased by using ANF. Mean systemic blood pressure was significantly decreased and these changes depended on the concentration of ANF. A significant increase of the in the plasma cGMP level was also observed with ANF. However, neither CBF nor heart rate was changed significantly. Pretreatment with HS (3 mg·kg -1 ) almost completely supplemented these hemodynamic effects of ANF along with inhibiting the increases of the cGMP level in the plasma. However, in control group, HS itself (3 mg·kg -1 , iv), had no significant change in coronary parameters. Conclusion:In patients with severe congestive heart failure, increased endogenous ANF may contribute to the regulation of coronary circulation as a compensatory mechanism.