Data/hora: 01/06/2024 04:30:59

Provedor de dados: 	56	
País: 	Brazil	
Título: 	Sera from chronic chagasic patients depress cardiac electrogenesis and conduction	
Autores: 	Costa,P.C.S.; Fortes,F.S.A.; Machado,A.B.; Almeida,N.A.C.; Olivares,E.L.; Cabral,P.R.; Pedrosa,R.C.; Goldenberg,R.C.; Campos-de-Carvalho,A.C.; Masuda,M.O.	
Data: 	2000-04-01	
Ano: 	2000	
Palavras-chave: 	Chagas' disease; Antibodies; Muscarinic activation; Beta-adrenergic activation; Gap junction; Mammalian heart.	
Resumo: 	We report results obtained with sera from 58 chronic chagasic patients that were evaluated for effects on heart rate and atrioventricular (AV) conduction in isolated rabbit hearts and screened for the presence of muscarinic and beta-adrenergic activity. We show that sera from 26 patients decreased heart rate, while 10 increased it and 22 had no effect. Additionally, sera from 20 of the 58 patients blocked AV conduction. Muscarinic activation seems to be involved in both effects, but is not the only mechanism, since atropine did not antagonize the decrease in heart rate in 23% of sera or AV block in 40%. Sera from patients with complex arrhythmias were significantly more effective in depressing both heart rate and AV conduction. Sera that induce increases in heart rate seem to operate exclusively through beta-adrenergic activation. Two of these sera, evaluated with respect to intercellular communication in primary cultures of embryonic cardiomyocytes were able to block gap junction conductance evaluated by a dye injection technique after 24-h exposure. The mechanisms underlying this uncoupling effect are currently being investigated.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000400010	
Editor: 	Associação Brasileira de Divulgação Científica	
Relação: 	10.1590/S0100-879X2000000400010	
Formato: 	text/html	
Fonte: 	Brazilian Journal of Medical and Biological Research  v.33 n.4 2000	
Fonte: 	info:eu-repo/semantics/openAccess