Abstract

LARREA, Fernando; SANCHEZ-GONZALEZ, Sergio; GARCIA-BECERRA, Rocío  and  MENDEZ, Isabel. Sites of prolactin inhibition on gonadotropin-induced estrogen production in cultured rat granulosa cells. Gac. Méd. Méx [online]. 2005, vol.141, n.4, pp.259-266. ISSN 2696-1288.

We studied the sites of prolactin inhibition upon FSH induced ovarian steroidogenesis and the ability of prolactin (Prl) to inhibit the synthesis of estradiol and cAMP accumulation under the stimulation of FSH or cAMP dependent activators. The participation of other signal pathways such as PKC and Gi proteins on the inhibitory actions of Prl was also investigated using calfostine C andpertusis toxin as inhibitors. Results showed a dose dependent prolactin decrease in FSH-induced estradiol and cAMP production prior and after the generation of the cyclic nucleotide by a mechanism involving the catalytic subunit of adenyl cyclase and/or through activation of PKC or by the interaction with pertusin toxin sensitive G proteins. Our results suggest a mechanism by which G protein coupled receptors are linked with those coupled with tyrosine kinase through the involvement of a Gi protein mediated mechanism.

Keywords : Prolactin; FSH; mechanisms of action; G proteins; granulosa cells; receptors.