title: Trypanosoma cruzi (CL strain) infection in mice changes the chronotropic effect of isoproterenol in vitro.
abstract: Cardiac autonomic denervation has been reported to occur in experimental T. cruzi infection. We used isoproterenol (IP) to investigate the in vitro chronotropic sensitivity of atrial beta-adrenoceptors from mice acutely (30 days) or chronically (180 days) infected with T. cruzi, CL strain (a myotropic strain). Displacement of the dose-response curve to IP to the right occurred in the acute phase group. In the chronic phase group the opposite effect occurred (hyperreactivity to IP) although to a lesser extent. These results suggest that infection of mice with this strain of T. cruzi induces quantitative or qualitative changes in atrial beta-adrenoceptors.
authors.affiliation: Departamentos de Ciências Fisiológicas e Patologia, Universidade Federal do Espírito Santo, Vitória, Brasil.
authors.forename: J G
authors.initials: JG
authors.lastname: Pires
authors.forename: F E
authors.initials: FE
authors.lastname: Pereira
mesh_terms: D000818:Animals; D002598:Chagas Cardiomyopathy / Q000503:physiopathology*; D004305:Dose-Response Relationship, Drug; D006325:Heart Atria / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects*; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009200:Myocardial Contraction; D011943:Receptors, Adrenergic, beta / Q000187:drug effects; D013268:Stimulation, Chemical; D014349:Trypanosoma cruzi
chemical_list: D011943:Receptors, Adrenergic, beta; D007545:Isoproterenol