Efeito vasorelaxante da estrona sobre aorta torácica de ratos: contribuição ao estudo do mecanismo de ação
Carregando...
Data
2014-09-19
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Goiás
Resumo
Endogenous estrogens have been associated with greater vascular protection
in premenopausal women, and the increased risk of cardiovascular diseases in
postmenopausal women can be associated to the decrease in plasma estrogen
levels. Furthermore recently studies showed that the use of estrogens, like estrone,
exhibits remarkable vascular effect when used on isolated arteries, however any
investigation was made to elucidate the mechanism of action of this compound. So,
the present study was designed to investigate the ability of estrone to induce
vascular relaxation and modulate NO-dependent signaling pathway and analyzed the
role of estrogens receptor on estrone-mediated vascular relaxation, compared with
the effects promoted by 17β-estradiol. 12 week-old male Wistar rats were used to the
vascular reactivity, which was performed in an organ bath study for an isometric
tension recording. To the experimental protocols, concentration-response curves (0.1
- 100μM) to estrone or 17β - estradiol were performed. The mechanism contributing
to estrone-induced effects were determined comparing with the vascular effects
induced by 17β - estradiol that have its effect vascular well characterized. It was
observed that the vascular relaxation promoted by estrone is dependent on the
endothelium and the estrogen receptor. The vasorelaxant effect promoted by estrone
was significantly altered in the presence of the inhibitor of PI3K signaling pathway
(wortmannin) and the Ca2+-CaM complex inhibitor (calmidazolium), showing the
involvement of PI3K/Ca2+-CaM signaling pathways. This study demonstrate that
estrone promoted vasorelaxant effect on rat thoracic aortic on endotheliumdependent
manner and its effect depends on the estrogen receptors that activate the
PI3K pathway and the Ca2+-calmodulin complex which subsequently activates the
NO/cGMP pathway. These results contribute to the better understanding of the role
of estrone in the conjugated equine estrogen (CEE) which could be associated to the
benefits effects of estrogens in the CEE therapy.
Descrição
Palavras-chave
Citação
OLIVEIRA, T. S. Efeito vasorelaxante da estrona sobre aorta torácica de ratos: contribuição ao estudo do mecanismo de ação. 2014. 52 f. Dissertação (Mestrado em Biologia) - Universidade Federal de Goiás, Goiânia, 2014.