Studies of membrane fluidity and heart contractile force in Trypanosoma cruzi infected mice
Mem. Inst. Oswaldo Cruz
; 99(7): 691-696, Nov. 2004. tab, graf
Article
em En
| LILACS
| ID: lil-391596
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BR1.1
RESUMO
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 percent 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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1
Índice:
LILACS
Assunto principal:
Trypanosoma cruzi
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Norepinefrina
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Receptores Adrenérgicos beta
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Doença de Chagas
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Fluidez de Membrana
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Contração Miocárdica
Limite:
Animals
Idioma:
En
Revista:
Mem. Inst. Oswaldo Cruz
Assunto da revista:
MEDICINA TROPICAL
/
PARASITOLOGIA
Ano de publicação:
2004
Tipo de documento:
Article