Basic fibroblast growth factor-induced prostaglandin production and its intracellular mechanisms in cultured bovine luteal cells

The effect of basic fibroblast growth factor (bFGF) on the production of prostaglandin (PG) F_2α and PGE₂, and the intracellular mechanisms of its action, were investigated in cultured bovine mid-luteal cells (days 8-12 of the estrous cycle). The cells were cultured for 24 h and then exposed to varying concentrations of bovine recombinant bFGF (rbFGF, 1-100 ng/ml) for a further 24 h. A 24-h stimulation with the highest concentration of rbFGF resulted in increases in both PGF_2α and PGE₂ production by mid-luteal cells (P<0.05). Both U-73122 (an inhibitor of phospholipase (PL) C, 10^-6 M) and anthranilic acid (ACA; an inhibitor of PLA₂, 10^-6 M) inhibited the rbFGF-induced PGF_2α and PGE₂ production (P<0.05). Moreover, following down-regulation of protein kinase C with a tumor-promoting phorbol ester, phorbol 12-myristate 13-acetate (PMA, 10^-6 M), the stimulatory effect of rbFGF was no longer evident. These results suggest that locally produced bFGF may play a role as one of the autocrine and/or paracrine stimulators of the production of PGs in bovine corpus luteum, and the stimulatory effect of bFGF on the production of PGs is mediated via the PLC-PKC-PLA₂ pathway.