BACKGROUND: Immune dysfunction has long been proposed as a mechanism for the etiopathogenesis of the chronic phase of Chagas' disease. Antibodies of chagasic patients have been shown to interfere with electric and mechanical activity of embryonic myocardial cells in culture. Here, we demonstrate that antibodies derived from a group of chronic chagasic patients are able to induce disturbances in the electrogenesis and conduction in isolated adult rabbit hearts. METHODS AND RESULTS: Sera from chronic chagasic patients with complex cardiac arrhythmias (ChA+) decreased heart rate (from 131+/-26 to 98+/-37 bpm [mean+/-SD]; n=6; P<.05) in isolated rabbit hearts when perfused at a dilution of 1:100 (vol:vol) by the Langendorff method. Sera from another experimental group of four chronic chagasic patients without complex arrhythmias (ChA-) and two control groups composed of five Wolff-Parkinson-White (WPW) syndrome patients and five orthopedic surgery patients did not affect heart rate when tested under similar conditions. In addition, sera from five of six ChA+ patients and from one WPW patient induced AV conduction blockade. Effects of the sera from ChA+ patients are due to their IgG fractions. Both serum and IgG effects are blocked by atropine (10 micromol/L). CONCLUSIONS: Antibodies of ChA+ patients decrease heart rate and induce AV conduction block in isolated adult rabbit hearts through activation of muscarinic receptors.
BACKGROUND: Immune dysfunction has long been proposed as a mechanism for the etiopathogenesis of the chronic phase of Chagas' disease. Antibodies of chagasic patients have been shown to interfere with electric and mechanical activity of embryonic myocardial cells in culture. Here, we demonstrate that antibodies derived from a group of chronic chagasic patients are able to induce disturbances in the electrogenesis and conduction in isolated adult rabbit hearts. METHODS AND RESULTS: Sera from chronic chagasic patients with complex cardiac arrhythmias (ChA+) decreased heart rate (from 131+/-26 to 98+/-37 bpm [mean+/-SD]; n=6; P<.05) in isolated rabbit hearts when perfused at a dilution of 1:100 (vol:vol) by the Langendorff method. Sera from another experimental group of four chronic chagasic patients without complex arrhythmias (ChA-) and two control groups composed of five Wolff-Parkinson-White (WPW) syndromepatients and five orthopedic surgery patients did not affect heart rate when tested under similar conditions. In addition, sera from five of six ChA+ patients and from one WPW patient induced AV conduction blockade. Effects of the sera from ChA+ patients are due to their IgG fractions. Both serum and IgG effects are blocked by atropine (10 micromol/L). CONCLUSIONS: Antibodies of ChA+ patients decrease heart rate and induce AV conduction block in isolated adult rabbit hearts through activation of muscarinic receptors.
Authors: Emiliano Horacio Medei; José Hamilton Matheus Nascimento; Roberto Coury Pedrosa; Antônio Carlos Campos de Carvalho Journal: Arq Bras Cardiol Date: 2008-10 Impact factor: 2.000
Authors: Simone Garcia; Carolina O Ramos; Juliana F V Senra; Fabio Vilas-Boas; Maurício M Rodrigues; Antonio C Campos-de-Carvalho; Ricardo Ribeiro-Dos-Santos; Milena B P Soares Journal: Antimicrob Agents Chemother Date: 2005-04 Impact factor: 5.191
Authors: Ciria C Hernandez; Jose H Nascimento; Elen A Chaves; Patricia C Costa; Masako O Masuda; Eleonora Kurtenbach; Antonio C Campos DE Carvalho; Luis E Gimenez Journal: J Recept Signal Transduct Res Date: 2008 Impact factor: 2.092
Authors: Diego F Dávila; Jose H Donis; Gabriela Arata de Bellabarba; Vanesa Villarroel; Francisco Sanchez; Lisbeth Berrueta; Siham Salmen; Barbara Das Neves Journal: Interdiscip Perspect Infect Dis Date: 2012-10-02
Authors: Paulo Marcos Matta Guedes; Cléber Mesquita de Andrade; Daniela Ferreira Nunes; Nathalie de Sena Pereira; Tamyres Bernadete Dantas Queiroga; George Luiz Lins Machado-Coelho; Manuela Sales Lima Nascimento; Maria Adelaide Do-Valle-Matta; Antônia Cláudia Jácome da Câmara; Egler Chiari; Lúcia Maria da Cunha Galvão Journal: PLoS Negl Trop Dis Date: 2016-04-26