title: Modification of the contractile activity of isolated atria by T4 lymphocytes from patients with Chagas' disease: effect of soluble factors.
abstract: The results of this study show that peripheral blood mononuclear leukocytes of patients with Chagas' disease (Ch-PBMC) respond to challenge with homologous as well as with heterologous heart antigens releasing active soluble factors capable of increasing the contractile tension and frequency of beating rat atria. The reaction was related to T. cruzi infection rather than to the presence of cardiomyopathy. Indirect evidence suggests that supernatants of Ch-PBMC activated with heart tissue homogenates involved the generation of arachidonic acid metabolites by the lipoxygenase system of rat atria. Active effector cells were present in Ch-PBMC that had been depleted of T8-lymphocytes by lysis with OKT8 and rabbit complement (C) and not in those depleted of T4-lymphocytes with OKT4 and C. Therefore, the positive inotropic and chronotropic effects of Ch-PBMC were due to the action of cells from the T4 subset.
mesh_terms: D000818:Animals; D016275:Atrial Function; D014355:Chagas Disease / Q000097:blood*; D002867:Chromones / Q000494:pharmacology; D006325:Heart Atria / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D009637:Masoprocol / Q000494:pharmacology; D009200:Myocardial Contraction / Q000187:drug effects; D051381:Rats; D013601:T-Lymphocytes / Q000502:physiology*
chemical_list: D002867:Chromones; D009637:Masoprocol; C006312:FPL 55712; D007213:Indomethacin