| First Author | Recouvreux MV | Year | 2011 |
| Journal | Endocrinology | Volume | 152 |
| Issue | 7 | Pages | 2722-30 |
| PubMed ID | 21521749 | Mgi Jnum | J:174905 |
| Mgi Id | MGI:5141390 | Doi | 10.1210/en.2010-1464 |
| Citation | Recouvreux MV, et al. (2011) Active and total transforming growth factor-{beta}1 are differentially regulated by dopamine and estradiol in the pituitary. Endocrinology 152(7):2722-30 |
| abstractText | Dopamine, acting through the dopamine type 2 receptor (Drd2), is the main inhibitor of pituitary prolactin (PRL) secretion and lactotroph proliferation. TGF-beta1 is involved, at least in part, in mediating these actions. It was described that TGF-beta1 synthesis in rat pituitary lactotrophs is up-regulated by dopamine and down-regulated by estradiol. TGF-beta1 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-beta1 content, as well as TGF-beta1 mRNA, and the in vivo role of dopamine and estradiol on pituitary TGF-beta1 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-beta1 mRNA expression, in active and total cytokine content, and in TGF-beta type II receptor expression. Dopamine regulation of pituitary TGF-beta1 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-beta1. PRL secretion correlated with active, but not total cytokine. TGF-beta1 inhibitory action on lactotroph proliferation and PRL secretion was decreased in Drd2(-/-) pituitary cells, in correlation with decreased TGF-beta type II receptor. The study of the TGF-beta1 activation process and its regulation is essential to understand the cytokine activity. As an intermediary of dopamine inhibition of lactotroph function, TGF-beta1 and local activators may be important targets in the treatment of dopamine agonist-resistant prolactinomas. |
