This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Carrasco, M. P. Articles by López Bernal, A. Search for Related Content PubMed Articles by Carrasco, M. P. Articles by López Bernal, A.

Activation of the prostaglandin FP receptor in human granulosa cells

Prostaglandin F₂ (PGF₂) has regulatory (mainly luteolytic) effects in the ovary but the mechanism of action is not completely understood. Reverse transcriptase–polymerase chain reaction (RT–PCR) techniques were used to demonstrate the presence of mRNA encoding the PGF₂ receptor (FP receptor) in human granulosa–lutein cells. Specific primers for the amplification of cDNA were designed and yielded a single product of 696 bp corresponding to the FP receptor. The identity of this product was verified by sequencing. Fluprostenol, a selective FP receptor agonist, activated phospholipase C (PLC) and increased intracellular free calcium concentration, confirming the functional activation of the receptor. We have demonstrated by Western blotting that granulosa cells express PLC-β and PLC- isoforms. The cells responded to pervanadate with increased PLC activity and increased tyrosine phosphorylation, demonstrating a functional PLC- tyrosine kinase pathway. However, fluprostenol did not provoke any detectable tyrosine phosphorylation. Moreover, the effect of fluprostenol was inhibited through protein kinase C stimulation by phorbol 12,13-dibutyrate, and was not affected when cells were treated with phenylarsine oxide, which blocks tyrosine phosphorylation. These results suggest that the FP receptor activates PLC-β rather than PLC- isoforms. Fluprostenol-induced activation was pertussis toxin resistant. Granulosa cells express G proteins of the G_q family (resistant to pertussis toxin) and mRNA for both G_q and G₁₁ has been identified by RT–PCR. In conclusion, human granulosa cells have a functional FP receptor the effects of which are mediated through PLC-β activation probably via G_q/11.