黄麻甲甙,哇巴因和康毗丁在豚鼠及猫心肺制备上强心作用的比较研究

本文报告强心药黄麻甲甙的治疗作用强度、治疗宽度并与已知强心药作比较性研究。在豚鼠、猫心肺制备上,以戊巴比妥钠引起心力衰竭(少数自发性心力衰竭),分别测定了黄麻甲甙、哇巴因、康毗丁的治疗作用及治疗宽度,以输出量或静脉压的改善作为、“治疗量”的指标;以静脉压重又上升,波幅加大,心律不齐作为“中毒量”指标;以发生心室纤维颤动作为“致死量”指标;计算了三种药物的治疗量/致死量、中毒量/致死量的百分率,黄麻甲甙在二种心肺制备上,对心力衰竭有良好的治疗作用,其治疗量在猫身上小于哇巴因;在豚鼠身上则与哇巴因相近,不仅作用较强,而且作用较其他二种已知强心甙发生得更早。在治疗量/致死量的百分率方面,在豚鼠心肺制备上,黄麻甲甙为6.05%、哇巴因17.45%、康毗丁14.41%。在猫心肺制备上则分别为10.86%、21.29%及22.96%;即黄麻甲甙的治疗宽度为上述二种强心甙的2～3倍,在统计学上有显著性差异。在中毒量/致死量的百分率方面,三种强心甙差异不大。本文对豚鼠心肺制备的实验方法及其作为测定强心甙治疗宽度的工具,作了简短的讨论。

COMPARATIVE STUDIES ON THE CARDIOTONIC ACTION OF CORCHOROSIDE A, OUABAIN AND STROPHANTHIN K ON THE HEART-LUNG PREPARATION OF GUINEA PIG AND CAT

The cardiotonic potency and therapeutic range of corchoroside A were compared with the well-known cardiac glycosides in heart-lung preparations of guinea pigs and cats. Heart failure was produced by adding pentobarbital sodium to the blood in the venous reservoir of heart-lung preparations (HLP) at a uniform rate (1mg/minute) in most experiments. In some other experiments the preparations were allowed to deteriorate spontaneously.A Steady fall in the cardiac output and right atrial pressure rise was taken as an indication of failure. The cardiac Competence test was used to assess the cardiac function by raising the venous reservoir by 5～10 cm for 15 seconds.The reduction in atrial pressure and the increased cardiac output were taken as an indicator of "threapeutic dose". Following the appearance of therapeutic effects the continued infusion of a cardiac glycoside results in cardiac irregularities. These irregularities are accompanied by a progressive reduction in the cardiac output and a concomitant abrupt rise in atrial pressure with widened pulse waves. These phenomena mentioned above were taken as an indicator of "toxic dose". Further continuation of the infusion results in ventricular fibrillation and was taken as an indicator of "lethal dose".The ratios of the threapeutic dose and toxic dose to the lethal dose in three glycosides have been expressed in per cent of the dose respectively. In the HLP of cats corchoroside A usually yielded higher therapeutic effect than ouabain and strophanthin K. In the HLP of guinea pigs its therapeutic dose was similar with ouabain and higher than strophantin K. Corchoraside A not only improved cardiac function and increased cardiac competence but the manifestation of cardiotonic action was earlier.Under our experimental conditions in the HLP of guinea pigs the per centage ratio of therapeutic dose/lethal dose was 6.05 for corchoroside A, 17.45 for ouabain, 14.41 for strophanthin K and in the HLP of cats 10.86, 21.29, and 22.96 respectively. Hence, corchoroside A has a 2～3 fold greater "safety margin" than the other two glycosides studied. It is statistically significant, The utilization of the HLP of guinea pigs as a novel tool for the determination of the therapeutic range of cardiac glycosides is also discussed.