磷酸羟基喹哌对豚鼠右室乳头状肌动作电位和收缩力的影响

本文采用常规微电极技术,研究了HPQP对豚鼠乳头状肌电和机械活动的影响。HPQP在10μmol/L以上是浓度依赖性地抑制收缩力,延长动作电位时程和有效不应期,低浓度时仅抑制V_(max),浓度在100μmol/L以上时可使动作电位幅度降低。在30μmol/L时能对抗乙酰胆碱缩短左房肌动作电位时程的作用。HPQP 100μmol/L能对抗哇巴因诱发的后振荡电位。结果提示:HPQP能非特异性地抑制Na~+,K~+和Ca~(2+)的跨膜转运。

Effect of hydroxypiperaquine phosphate on action potential and contractive force of guinea pig's heart muscles

The effects of hydroxypiperaquine phosphate(HPQP)on the electrical and mechanical activities of the isolated right ventricular papillary muscles of guinea pigs were studied by means of conventional glass microelectrodes.HPQP at 30μmol/L inhibited contractive force from 100% of control to 70.6% and decreased maximal upstroke velocity(Vmax)from 270±SD 44 V/s to 238±39 V/s.At the same concentration,HPQP prolonged action potential duration at 20 and 90% repolarization(APD20,APD90)from 116±15ms to 125±14 ms and from 230±15 ms to 238±16 ms,respectively.The effective refractory period(ERP)was distinctly increased from 214±20 ms to 235±19 ms.HPQP at 100μmol/L reduced the amplitude of action potential(APA)from 118±5 mVto 114±7 mV.All these results showed a concentration-dependent manner above 10μmol/L.Other results from auricle demonstrated that HPQP at 30μmol/L could antagonize the effect of ACh(10μmol/L)on shortening APD.Moreover,HPQP at 100μmol/L diminished or eliminated the oscillatory potential induced by ouabain(0.4-1.5μmol/L).These results indicate that HPQP may unspecifically inhibit the transmembrane currents of Na+,Ca2+ and