[Electrophysiological analysis of the effects of 4-amino-pyridine in the isolated heart ventricle of the guniea pig].
The effects of 4-aminopyridine (4-AP) on guinea pig myocardial ventricular isolated strips were studied by means of intracellular microelectrodes. 4-AP increased the maximal depolarization velocity and decreased the effects of quinidine. In contrast to adrenaline, 4-AP antagonized the effects of MnCl1, but was ineffective against the alterations induced by a sodium poor solution. These findings support the suggestion that 4-AP modifies the electrophysiological membrane properties probably by increasing the Na+ inward current.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002712:Chlorides / Q000494:pharmacology; D004558:Electric Stimulation; D004837:Epinephrine / Q000494:pharmacology; D006168:Guinea Pigs; D006329:Heart Conduction System / Q000187:drug effects*; D006352:Heart Ventricles / Q000187:drug effects; D066298:In Vitro Techniques; D008345:Manganese / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects*; D011725:Pyridines / Q000494:pharmacology*; D011802:Quinidine / Q000494:pharmacology; D012964:Sodium / Q000494:pharmacology; D016276:Ventricular Function
D002712:Chlorides; D011725:Pyridines; D008345:Manganese; D012964:Sodium; D011802:Quinidine; D004837:Epinephrine
Analyse electrophysiologique des effets de l'amino-4 pyridine sur le lambeau ventricularie isolé de coeur de cobaye