title: [Effect of a new beta-blocker (CM 6805) on the action potential of guinea pig atrial fiber].
abstract: CM6804 effect has been studied about some parameters of the intracellular action potential (AP) of guinea pig autorythmic auricle. Auricle was preserved alive under Tyrode oxygenated solution at 37 degrees C. AP is measured by a fluctuating intracellular glass microelectrode. At a concentration of 5 . 10(-5) M, CM doesn't alter the resting membrane potential, it causes a small overshoot reduction, it decreases the maximum depolarization rate and the heart rate, it increases the action potential duration. Overshoot and maximum depolarization rate decrease prove that CM modifies the membrane permeability probably by a diminution of the sodium rapid inward current. CM action is similar to others aryl-oxy-propyl propanolamine like propranolol.
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D016275:Atrial Function; D004336:Drug Antagonism; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects*; D006325:Heart Atria / Q000187:drug effects; D007545:Isoproterenol / Q000494:pharmacology; D009200:Myocardial Contraction / Q000187:drug effects; D011412:Propanolamines
chemical_list: D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; C036631:butofilolol; D007545:Isoproterenol
vernacular_title: Effetto di un nuovo beta-bloccante (CM 6805) sul potenziale di azione della fibra atriale di cavia.