EPIDERMAL DERIVED GROWTH-FACTOR STIMULATES THE PROSTAGLANDIN-F2-ALPHA-SYNTHESIS IN RABBIT LUTEAL CELLS

Isolated rabbit luteal cells from day 6 and 12 of pseudopregnancy were cultured with hCG, EGF, and EGF together with arachidonic acid (AA) in serum-free culture medium for 96 hours. The hCG stimulation of the progesterone (P) synthesis was more pronounced on day 6 then on day 12. EGF alone did not change significantly the production of either P or PGF2alpha. AA increased the production of PGF2alpha on day 6 and 12 significantly (3.9-fold on day 6, P < 0.005; 7-fold on day 12, P < 0.001). AA together with EGF increased the level of PGF2alpha more pronounced when compared with AA alone (7.2-fold on day 6, P < 0.025; 9.8-fold on day 12, P < 0.05). The progesterone production of the cells remained unchanged during EGF exposure. We conclude that EGF together with AA is able to stimulate the PGF2alpha biosynthesis in cultured rabbit luteal cells. Therefore, EGF could be relevant as an additional regression factor in rabbits. This mechanism seems to be independent from the progesterone synthesis.