Influence of the estrous cycle on the norepinephrine-induced contraction of rat aorta: relationship to vascular prostanoids biosynthesis
Biol. Res
; 27(3/4): 209-15, 1994. tab, graf
Article
em En
| LILACS
| ID: lil-228581
Biblioteca responsável:
BR1.1
ABSTRACT
Since ovarian sex steroids (estradiol and progesterone) may affect both blood pressure and prostanoids synthesis, and because prostaglandin-E2 (PGE2) and prostacyclin (PGI2) can modulate the vascular action of pressor hormones, we investigated the vascular reactivity to norepinephrine during the estrous cycle of the rat. In addition, we determined the vascular biosynthesis of PGE2 and 6-keto-PGF1 alpha (the stable metabolite of PGI2) at different stages of the estrous cycle. Cumulative dose-response curves were obtained by a stepwise increase in the concentration of norepinephrine. The contraction of thoracic aortic rings induced by norepinephrine did not change significantly between estrus, metestrus and diestrus. However, aortic rings obtained on proestrus showed a significant reduction in the maximal contraction (Emax) induced by norepinephrine (p < 0.001). In addition, we found significant increases in vascular synthesis of PGE2 and PGI2 on proestrus (p < 0.001). These results indicate that vascular reactivity and vascular prostanoids synthesis are influenced by the hormonal changes occurring during the estrous cycle of normal female rats. It is possible that prostanoids generated locally may play an important role in the regulation of vasomotor tone in the systemic vascular bed throughout the estrous cycle
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Coleções:
01-internacional
Base de dados:
LILACS
Assunto principal:
Aorta Torácica
/
Estro
/
Norepinefrina
/
Prostaglandinas
Limite:
Animals
Idioma:
En
Revista:
Biol. Res
Assunto da revista:
BIOLOGIA
Ano de publicação:
1994
Tipo de documento:
Article
País de publicação:
Chile