title: Chronotropic and inotropic responses to ASL-7022 on isolated rat atria.
abstract: ASL-7022 is a new synthetic catecholamine with alpha and beta adrenoceptor stimulating activity having inotropic selectivity in vivo. On the isolated rat atria, ASL-7022 produced concentration-dependent increases in spontaneous rate, developed tension (DT) and maximal velocity of contraction (+T). The maximal chronotropic and inotropic responses to ASL-7022 were similar to those obtained with isoproterenol, although the compound was less potent than isoproterenol. The inotropic and chronotropic effects of ASL-7022 were sensitive to propranolol blockade and were not affected by prazosin blockade. When the inotropic selectivity of ASL-7022 was analyzed, it was found that, like isoproterenol, each concentration of the agonist produced greater chronotropic than inotropic effect. Our results indicate the lack of an alpha 1-mediated component in the chronotropic and inotropic effects of ASL-7022 and the absence of inotropic selectivity in vitro.
authors.affiliation: Centro de Investigaciones Cardiovasculares, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Argentina.
authors.forename: O A
authors.initials: OA
authors.lastname: Gende
authors.forename: M C
authors.initials: MC
authors.lastname: Camilión de Hurtado
mesh_terms: D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology*; D002395:Catecholamines / Q000494:pharmacology*; D055598:Chemical Phenomena; D002621:Chemistry; D004357:Drug Synergism; D005260:Female; D006325:Heart Atria / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects*; D007545:Isoproterenol / Q000494:pharmacology*; D009200:Myocardial Contraction / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D013268:Stimulation, Chemical
chemical_list: D002316:Cardiotonic Agents; D002395:Catecholamines; C036054:ASL 7022; D007545:Isoproterenol