氯化镓对豚鼠心室肌动作电位变化及收缩的影响。
Effects of gallium chloride on changes in action potentials and contraction in guinea pig ventricular muscle.
作者信息
Kantelip J P, Millart H, Leperre A, Mougin F, Didier J M
机构信息
Laboratorie de Pharmacologie Fondamentale, Faculté de Médecine, Besançon, France.
出版信息
Anticancer Res. 1996 Jan-Feb;16(1):327-32.
The electrophysiological effects of gallium chloride (Ga ) and its activity on arrhythmias induced by digitalis were investigated in guinea pig papillary muscle. KCl microelectrodes were used to record transmembrane electrical activity from Purkinje cells from the papillary muscle of guinea pig hearts during superfusion and electrical stimulation in vitro at 37 degrees C. Myocardial contractility was continuously monitored. Ga was superfused alone in cumulative concentrations(4.5 . 10(-5) to 3.6 . 10(-4) M). Arrhythmias were induced by a superfusion of Digitoxin (7.5 . 10 (-7) M). A superfusion of Ga (4.5 . 10(-5), 9 . 10(-5), 1.8 . 10(-4) M and 3.6 . 10(-4) M) was started 20 min later and maintained for 70 min. Ga alone produced a dose dependent reduction of action potential duration and contractility. Ga potentiated the decrease in the amplitude and duration of the action potential induced by Digitoxin. The incidence of arrhythmias was immediately reduced by two concentrations of Ga (4.5 . 10(-5) and 9 . 10(-5) M) in the digitalized papillary muscles. It is concluded that Ga inhibits calcium movements and has negative inotropic and antidysrhythmic effects.
在豚鼠乳头肌中研究了氯化镓（Ga）的电生理效应及其对洋地黄所致心律失常的作用。采用氯化钾微电极记录37℃体外灌流和电刺激时豚鼠心脏乳头肌浦肯野细胞的跨膜电活动。连续监测心肌收缩性。单独以累积浓度（4.5×10⁻⁵至3.6×10⁻⁴M）灌流Ga。用洋地黄毒苷（7.5×10⁻⁷M）灌流诱发心律失常。20分钟后开始灌流Ga（4.5×10⁻⁵、9×10⁻⁵、1.8×10⁻⁴M和3.6×10⁻⁴M）并持续70分钟。单独的Ga产生剂量依赖性的动作电位时程和收缩性降低。Ga增强了洋地黄毒苷所致动作电位幅度和时程的减小。在洋地黄化的乳头肌中，两种浓度的Ga（4.5×10⁻⁵和9×10⁻⁵M）可立即降低心律失常的发生率。结论是Ga抑制钙转运，具有负性肌力作用和抗心律失常作用。
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