English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We have determined the time course of phosphorylation of MAPK/ERK, cAMP-responsive element-binding protein (CREB), and serine/threonine kinase (Akt) in ovine pituitary gonadotropes after in vivo injection (iv) of either 25 mug estradiol-17beta (E17beta) or vehicle. In ovariectomized ewes, E17beta increased the number of gonadotropes expressing phosphorylated (p)ERK-1/2 and pCREB immunoreactivity (-IR) within 90 min, as assessed by immunohistochemistry. By Western blot, we also showed that pERK-1/2, pCREB, and pAkt (ser 473) proteins were up-regulated by E17beta. In ovariectomized, hypothalamo-pituitary-disconnected animals, gonadotrope function was restored with hourly GnRH pulses (iv), and E17beta injection (iv) reduced LH response within 1 h. Immunohistochemistry showed that E17beta increased pERK-1/2-IR in gonadotropes within 15 min and peak response at 60 min. The number of cells immunoreactive for pCREB was greater in E17beta-treated animals than in vehicle-injected controls at 60 and 90 min. Western blot revealed a pERK-1/2 response within 15 min and pCREB response at 30 min. Up-regulation of pAkt occurred within 60 min of E17beta treatment. Thus, rapid effects of E17beta on gonadotropes involve phosphorylation of second messenger proteins with a time course that may relate to the rapid negative feedback effect to reduce responsiveness to GnRH.

endocrinology

Rapid in Vivo Effects of Estradiol-17β in Ovine Pituitary Gonadotropes Are Displayed by Phosphorylation of Extracellularly Regulated Kinase, Serine/Threonine Kinase, and 3′,5′-Cyclic Adenosine 5′-Monophosphate-Responsive Element-Binding Protein