【摘要】 本文结果表明,灭吐灵能明显提高乌头碱致大白鼠心律失常的用量。灭吐灵能产生浓度依赖性的负性肌力作用,并使动作电位零相上升的最大速率(dV/dt_ma X)降低,半效抑制浓度(IC₅₀)分别为4.22×10^-5M和5.31×10^-5M。灭吐灵(10^-6M～3×10^-5M)不影响动作电位幅度（APA）、动作电位复极20％及90％时的时程(APD₂₀、APD₉₀)。高浓度时(10^-4M)才降低APA,缩短APD₂₀、APD₉₀。灭吐灵不影响静息电位（RP）。除dV/dt_max外,多巴胺(3×10^-6M)能逆转灭吐灵(10^-4M)的全部效应。更多还原

【Abstract】 Metoclopramide (iv.20mg/kg) increased markedly the amount of aconitine necessary to produce cardiac arrhythmias in anesthetized rats.We observed the influence of metoclopramide on action potential and contractile force in isolated guinea pig papillary muscles.The results shown that 1) metoclopramide reduced contractile force and dV/dtmax IC50 were 4.22×10-5M and 5.31×10-5M respectively; 2) metoclopramide (10-6M-3×10-5M) has no effect on APA,APD20,APD90,higher concentration (10-4M) decreased APA and shortened APD20 and A’PD90;3) metoclopramide has no significant effect on RP; 4) dopamine (3×10-6M) can reverse all effects of metoclopramide (10-4M),except dV/dtmax.更多还原