Effects of dopamine and tamoxifen on serum prolactin and nuclear estrogen receptors in rat anterior pituitaries
Serum prolactin (PRL) and pituitary nuclear estrogen receptors (RnE2) were determined in ovariectomized rats treated with 5 μg/kg estradiol and subjected to single or combined treatment with dopamine (DA) and tamoxifen (TAM). A significative inhibition of serum PRL was observed by DA, TAM, and DA pl...
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1993
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0172780X_v15_n5-6_p389_Stalldecker http://hdl.handle.net/20.500.12110/paper_0172780X_v15_n5-6_p389_Stalldecker |
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| Sumario: | Serum prolactin (PRL) and pituitary nuclear estrogen receptors (RnE2) were determined in ovariectomized rats treated with 5 μg/kg estradiol and subjected to single or combined treatment with dopamine (DA) and tamoxifen (TAM). A significative inhibition of serum PRL was observed by DA, TAM, and DA plus TAM treatment. TAM, as well as DA, increased RnE2, but DA reduced the TAM effect when they were administered together. This observation suggests competition for a common binding site on the RnE2 between TAM and DA or by an unknown ligand produced after treatment with DA. The lack of an additive effect on PRL inhibition in the combined treatment indicates that both agents share at least one common inhibitory mechanism for PRL, behaving as antagonists of estrogen action at the receptor level. |
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