多培沙明,非诺多泮和丙卡特罗对心肌缺血时电生理变化影响的比较

新型多巴胺受体激动剂多培沙明(DPX)能显著减轻缺氧和缺血豚鼠心室乳头肌静息电位,动作电位幅度和O相除极速度的降低程度及动作电位时程的缩短程度,其减轻作用明显大于非诺多泮(FODA)和丙卡特罗(PCTR)。DPX能使缺氧时缩短的有效不应期(ERP)延长,而使缺血时延长的ERP缩短,其程度明显大于FODA与PCTR。提示DPX抗缺血性心律失常的作用优于其他类型的多巴胺激动剂。

EFFECTS OF DOPEXAMINE ON THE ELECTROPHYSIOLOGIC CHANGES DURING MYOCARDIAL ISCHEMIA AND COMPARISON WITH FENOLDOPAM AND PROCATEROL

The effects of dopexamine(DPX),a new dopamine receptor agonist ,ontransmembrane potential and effective refractory period(ERP)of isolated guinea pig ventricularmuscle superfused either with hypoxia or mimic ischemia perfusates were investigated by usingintracellular microelectrede technique and compared with fenoldopam(FODA) and procaterol.DPX(3 ×10^-6mol·L^-1) was found to significantly reduce both the extent of decrease of resting poten-tial ,action potential amplitude and maximal upstroke velocity and the degree of shortening of actionpotential duration caused by hypoxia or ischemia,These effects of DPX were significantly greater thanthose of FODA and procaterol albeit the latter showed effects similar to DPX,DPX could not onlylengthen the abbreviated ERP resulting from hypoxin,but also shorten the prolonged ERP caused byischemia.This action of DPX was more evident than that of FODA and procaterol.The results revealthe potential advantages of DPX over other dopaminergic agonists in the antiarrhythmic activity duringmvocardial ischemia.