Studies of membrane fluidity and heart contractile force in Trypanosoma cruzi infected mice

Autor: Julio E Enders, A Ruth Fernández, Héctor W Rivarola, Patricia A Paglini, José A Palma
Jazyk: angličtina
Rok vydání: 2004
Předmět:
Zdroj: Memorias do Instituto Oswaldo Cruz, Vol 99, Iss 7, Pp 691-696 (2004)
Druh dokumentu: article
ISSN: 0074-0276
1678-8060
DOI: 10.1590/S0074-02762004000700005
Popis: In Chagas disease serious cardiac dysfunction can appear. We specifically studied the cardiac function by evaluating: ventricle contractile force and norepinephrine response, affinity and density of beta-adrenergic receptors, dynamic properties of myocardial membranes, and electrocardiography. Albino swiss mice (n = 250) were infected with 55 trypomastigotes, Tulahuen strain and studied at 35, 75, and 180 days post-infection, that correspond to the acute, indeterminate, and chronic phase respectively. Cardiac beta-adrenergic receptors' affinity, myocardial contractility, and norepinephrine response progressively decreased from the acute to the chronic phase of the disease (p < 0.01). The density (expressed as fmol/mg.prot) of the receptors was similar to non-infected mice (71.96 ± 0.36) in both the acute (78.24 ± 1.67) and indeterminate phases (77.28 ± 0.91), but lower in the chronic disease (53.32 ± 0.71). Electrocardiographic abnormalities began in the acute phase and were found in 65% of the infected-mice during the indeterminate and chronic phases. Membrane contents of triglycerides, cholesterol, and anisotropy were similar in all groups. A quadratic correlation between the affinity to beta-adrenergic receptors and cardiac contractile force was obtained. In conclusion the changes in cardiac beta-adrenergic receptors suggests a correlation between the modified beta-adrenergic receptors affinity and the cardiac contractile force.
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