ELECTROMECHANICAL EFFECTS OF NEWLY SYNTHESIZED PROPAFENONE DERIVATIVES ON ISOLATED GUINEA-PIG HEART-MUSCLE PREPARATIONS

Inotropic, chronotropic and beta-adrenoceptor blocking activities of t he newly synthetized propafenone derivatives amino-2-hydroxypropoxy)ph enyl-3-phenyl-1-propanone hydrochloride (AM 03), -(1-piperidyl)propoxy )phenyl)-3-phenyl-1-propanone hydrochloride (AM 05), thyl-N-(2-hydroxy -3-(2-(3-phenylpropionyl)phenoxy) propyl)-propylammonium iodide (TH 41 ), N,N-diethyl-N-(2 -(3-phenylpropionyl)phenoxy)propyl)-methylammonium iodide (AM 07), and -(3-phenylpropionyl)phenoxy)propyl)-methylammoniu m iodide (AM 09) studied in isolated, electrically stimulated papillar y muscles and spontaneously beating right atria of guinea pigs. In com parison with propafenone the tertiary amines AM 03 and AM 05 showed a higher negative inotropic potency, while the quarternary amines TH 41, AM 07 and AM 09 were less effective. With regard to their negative ch ronotropic action, AM 03 and AM 05 were more and TH 41, AM 07 and AM 0 9 less potent than the parent drug. In contrast to propafenone none of its derivatives exerted beta-adrenoceptor blockade at the concentrati ons studied.