Effects of acute and chronic estrogenic treatment on vasomotor responses of aortic rings from ovariectomized rats.
Life Sci
; 57(5): 473-86, 1995.
Article
em En
| MEDLINE
| ID: mdl-7623614
The effects of either chronic or acute estrogenic treatment on the "in vitro" vasomotor responses to phenylephrine (10(-9)-10(-5) M) and to carbachol (10(-9)-10(-5) M) of aortic rings excised from ovariectomized rats were analyzed. Chronic estrogenic treatment consisted in a single subcutaneous dose of 1 mumol estradiol 17-stearate. Effects of acute estrogenic treatment were evaluated by recording the responses of aortic rings excised from untreated ovariectomized rats both before and after the addition of 17 beta-estradiol to the superfusing solutions. In order to identify the endothelium-dependent responses each experiment was performed simultaneously on pairs of rings from the same aorta, one with and the other without functional endothelium. The contractile responses to phenylephrine of endothelium-intact vessels were attenuated by chronic estrogenic treatment; this attenuation was further increased by preincubation of the vessels with indomethacin and was reverted by N omega-nitro-L-arginine methyl ester. Either chronic or acute estrogenic treatment enhanced the carbachol-induced endothelium dependent relaxation of phenylephrine-precontracted rings. The results may be explained by assuming that estrogens increase the basal release of both nitric oxide and a cyclooxygenase-dependent vasoconstricting prostanoid as well as the receptor-mediated release of nitric oxide from the endothelium of the rat aorta.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Aorta
/
Vasoconstrição
/
Vasodilatação
/
Estradiol
Limite:
Animals
Idioma:
En
Revista:
Life Sci
Ano de publicação:
1995
Tipo de documento:
Article
País de afiliação:
México
País de publicação:
Holanda