间硝苯啶与美托洛尔合用对兔血液动力学的影响

EFFECT OF M-NIFEDIPINE AND METOPROLOL IN COMBINATION ON THE HEMODYNAMICS IN RABBITS

用阻抗法测定间硝苯啶(m-Nif)和美托洛尔(Met)对清醒兔血液动学力的影响。m-Nifiv(20μg/kg)或十二指肠给药(0.25 mg/kg)可增加心脏指数、降低总外周阻力及血压,而对心率无影响。m-Nif与等量或5倍量Met合用时,可减慢心率,并保持m-Nif的上述作用。m-Nif与两种剂量Met合用的作用差别是后者心率减慢更为明显。结果提示,m-Nif与小剂量Met合用是可取的,尤其在高血压和冠心病伴有心率增快的患者是有利的。

Hemodynamic effects of m- nifedipine (m- Nif) combined with metoprolol (Met)were studied in conscious rabbits with impedance cardiography. Administration of m - Nif by intravenous injection (20μg/kg) or by intraduodenal route (0.25 mg/kg) increased cardiac index (CI) and redused total peripheral resistance (TPR)and arterial pressure. Intravenous injection of Met significantly slowed heart rate without great change in other hemodynamic parameters in conscious rabbits. Combination of m- Nif with Met gained the advantages of both m- Nif and Met. The negative effects of Met on CI and TPR were balanced by the vasodilatory effect of m- Nif. The difference between the results of m-Nif combined with equal dose of Met or with fivetimes the dose of Met was just that further decrease of heart rate was observed. These results suggest that combined administration of m- Nif with Met may be more beneficial than giving each drug alone. It may be more suitable to use m- Nif combined with low doses of Met in order to avoid the danger of depressing myocardium.