| Autor: |
Ignacio, Valencia-Hernández, José Antonio, Reyes-Ramírez, Héctor, Urquiza-Marín, Blanca, Nateras-Marín, José Carlos, Villegas-Bedolla, Daniel, Godínez-Hernández |
| Rok vydání: |
2012 |
| Předmět: |
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| Zdroj: |
Pharmacology. 90(5-6) |
| ISSN: |
1423-0313 |
| Popis: |
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 17β-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. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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