汉防己甲素对左心室功能及外周血管的影响

麻醉狗急性实验表明,静脉注射汉防己甲素引起降压的同时,伴有LVP、±dp/dt max(左心室压正负向变化最大速率)的降低。但LVP和±dp/dt max的恢复先于血压的恢复。提示其对左心室收缩功能的抑制仅与初期降压效应部分有关。本品降低血压和外周阻力以及减慢心率的作用较持久,其对舒张压的降低作用大干对收缩压的影响。结果表明汉防己甲素的降压效应主要系通过扩张阻力血管所致。

INFLUENCE OF TETRANDRINE ON THE LEFT VENTRICULAR FUNCTION AND PERIPHERAL BLOOD VESSELS IN CANINES

Tetrandrineis an alkaloid isolated from the Chinese medicinal herb, Stephania tetrandra S. Moore. It has been shown clinically to be an effective antihypertensive drug. Its effects to dilate the coronary vasculature, to reduce the toxicity of cardiac glycosides and to correct cardiac arrhythmias have been demonstrated in the laboratory.This paper presents results of an experimental study of the influence of Tetrandrine on the left ventricular function and peripheral blood vessels in anesthetized openchest dogs.Tetrandrine given intravenously (10mg/kg and 15mg/kg) lowered the systemic blood pressure, decreased LVP and dp/dt max. The decreased LVP and dp/dt max recovered more rapidly than the systemic blood pressure. It is suggested that this cardiac inhibitory effect contributed at least in-part to the early hypotensive effect.Concomitant with its hypotensive effect, Tetrandrine caused a decrease of heart rate and a prolongation of P-R interval.The drug produced a marked reduction of the peripheral resistance which paralleled its effect on blood pressure. In addition, the pulse pressure was increased because the amount of decrease Of diastolic blood pressure was larger than that of the systolic. It may be concluded that this drug depresses blood pressure mainly by its dilatatory action on the resistant blood vessels.