Active and Total Transforming Growth Factor-{beta}1 are Differentially Regulated by Dopamine and Estradiol in the Pituitary

Autores
Recouvreux, Maria Victoria; Guida, María Clara; Rifkin, Daniel B.; Becu, Damasia; Diaz, Graciela Susana
Año de publicación
2011
Idioma
inglés
Tipo de recurso
artículo
Estado
Versión publicada
Descripción
Dopamine, acting through the dopamine type 2 receptor (Drd2), is the main inhibitor of pituitary prolactin (PRL) secretion and lactotroph proliferation. TGF-β1 is involved, at least in part, in mediating these actions. It was described that TGF-β1 synthesis in rat pituitary lactotrophs is up-regulated by dopamine and down-regulated by estradiol. TGF-β1 is secreted as a large latent complex. The local regulation of cytokine activation in the pituitary has not yet been explored. In this work, we studied pituitary active and total TGF-β1 content, as well as TGF-β1 mRNA, and the in vivo role of dopamine and estradiol on pituitary TGF-β1 levels. Adult female mice (wild type), and female mice with a null mutation in the Drd2 (Drd2−/−), were used. The loss of dopaminergic tone induced a decrease in TGF-β1 mRNA expression, in active and total cytokine content, and in TGF-β type II receptor expression. Dopamine regulation of pituitary TGF-β1 activation process was inferred by the inhibition of active cytokine by in vivo sulpiride treatment. Interestingly, in the absence of dopaminergic tone, estradiol induced a strong increase in active TGF-β1. PRL secretion correlated with active, but not total cytokine. TGF-β1 inhibitory action on lactotroph proliferation and PRL secretion was decreased in Drd2−/− pituitary cells, in correlation with decreased TGF-β type II receptor. The study of the TGF-β1 activation process and its regulation is essential to understand the cytokine activity. As an intermediary of dopamine inhibition of lactotroph function, TGF-β1 and local activators may be important targets in the treatment of dopamine agonist-resistant prolactinomas.
Fil: Recouvreux, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina
Fil: Guida, María Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina
Fil: Rifkin, Daniel B.. University Of New York; Estados Unidos
Fil: Becu, Damasia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina
Fil: Diaz, Graciela Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina
Materia
ACTIVE TGFb1
PITUITARY
ESTRADIOL
DOPAMINE
Fisiología
Medicina Básica
CIENCIAS MÉDICAS Y DE LA SALUD
Nivel de accesibilidad
Acceso restringido
Licencia
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/11210