The effects of 17ß-oestradiol on increased α(1)-adrenergic vascular reactivity induced by prolonged ovarian hormone deprivation: the role of voltage-dependent L-type Ca channels.
Pharmacology
; 90(5-6): 316-23, 2012.
Article
en En
| MEDLINE
| ID: mdl-23037569
ABSTRACT
The present study investigated the hypothesis that the duration of ovarian hormone deprivation before reintroduction of oestrogen affects the role of oestrogen as a mediator of the contractile function of α(1)-adrenergic receptors. Rats underwent ovariectomy (OVX) or were sham-operated, and the OVX rats were treated with vehicle (corn oil) or 17ß-oestradiol (E(2)) for 5 days either 10, 28 or 60 days after OVX. The OVX increased phenylephrine- and Ca(2+)-induced contractions. Interestingly, the phenylephrine-induced contractions were increased at each of the three time points, whereas the Ca(2+)-induced contractions were only increased in the 60-day group. E(2) had biphasic effects on phenylephrine- and Ca(2+)-induced contractility. Indeed, E(2) increased contractions in the 10-day group and diminished contractions in the other groups (the increased contractions were avoided by verapamil). These results indicate that E(2) controls α(1)-adrenergic receptor-mediated contractility through effects on L-type Ca(2+) channels in a way that depends on the timing in which the treatment with E(2) is initiated.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Ovariectomía
/
Receptores Adrenérgicos alfa 1
/
Canales de Calcio Tipo L
/
Estradiol
/
Estrógenos
Límite:
Animals
Idioma:
En
Revista:
Pharmacology
Año:
2012
Tipo del documento:
Article