间硝苯啶对猫冠脉流量,心肌耗氧量的量效关系

Relationship between dose and effect of meta-nifedipine on coronary flow and myocardial oxygen consumption in cats

不同剂量m-Nif 10,20,40μg·kg^(-1)iv显著增加猫冠脉血流量(CBF),并呈明显量效反应关系,按作用峰值计算,分别增加原水平30,68,94％,Nif-20μg·kg^(-1)增加原水平49％,同时显著降低心肌耗氧量(MOC),按作用峰值计算,分别降低原水平29,46,55％,Nif降低原水平45％,心肌氧摄取减少,m-Nif分别减少原水平31,44,54％,Nif43％,血压分别降低原水平39,42,50％,Nif45％,m—Nif明显减慢心率,Nif则不减慢心率.m—Nif在40μg·kg^(-1)iv增加冠脉流量远较其他剂量强而持久,Nif较同量m-Nif作用弱而短。

The action of different doses of meta-nifedipine (m-Nif), a new calcium antagonist, and Nif on coronary sinus blood flow, myocardial oxygen consumption, blood pressure and heart rate was monitored in anesthetized cats. All three different doses of m-Nif increased in coronary blood flow. Three minutes (peak effects of time) after administration of m-Nif 10 μg·?kg-1 iv (n = 6) coronary flow started to increase from 0.71± s 0.07 to 0.92± s 0.07 ml·min-1·g-1 (+30%). m-Nif 20 μg·kg1 iv increased from 0.68± s 0.07 to 1.14± s 0.09 ml·min1·g-1 (+68%), Nif 20μg ·kg -1 iv increased from 0.70± s 0.07 to 1.04±s 0.08 ml·min-1·g-1 (peak effect of time is 1 min +49%), m-Nif 40 μg·kg-1 iv (n = 6) increased from 0.78± s 0.08 to 1.51± s 0.11 ml·min-1·g-1 (peak effect of time is 10 min, 94%) with a potency higher and the duration of action longer than that of m-Nif 10, 20μg·kg-1 and Nif 20 μg·kg-1. Three different doses of m-Nif and Nif reduced myocardial oxygen consumption and blood pressure and heart rate with relationships between effects and doses. The results indicated that m-Nif has more beneficial in alleviating myocardial ischemia than that of Nif.