Effect of trimebutine maleate on sinus node pacemaker activity of the rabbit.
The electrophysiological effects of trimebutine maleate were studied on rabbit sinus node cells with the two-microelectrode voltage clamp method. Trimebutine (above 10 microM) produced a negative chronotropic effect accompanied by decreases in the maximum upstroke velocity at phase 0, slope of phase 4 depolarization and action potential amplitude. The effects on the current systems were depression of the slow inward current and a decrease in the current oscillations induced by elevating [Ca]0. It is concluded that trimebutine exerts a Ca2+ channel blocking effect on the sinus node pacemaker cells.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001565:Benzoates / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D004594:Electrophysiology; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D007473:Ion Channels / Q000187:drug effects / Q000378:metabolism; D011817:Rabbits; D012849:Sinoatrial Node / Q000187:drug effects* / Q000502:physiology; D014287:Trimebutine / Q000494:pharmacology*
D001565:Benzoates; D007473:Ion Channels; D014287:Trimebutine; D002118:Calcium