The effect of prostaglandins in the rat ovary: specific or unspecific stimulation of cAMP, cGMP and progesterone?

Abstract

Abstract. Ovarian membranes of the rat do not specifically bind prostaglandin E2 at any stage of development. Attachment of [3H]prostaglandin E2 in the presence of an excess of unlabelled prostaglandin E2 increased in a linear fashion and was not saturable. Prostaglandin E2 stimulated cAMP accumulation by ovarian cells of all developmental stages. This effect was not saturable. An effect of prostaglandin E2 on cGMP levels was not observed. At high concentrations of prostaglandin E2 an increase of ovarian progesterone synthesis was detected. In comparison hCG stimulated progesterone synthesis at much lower concentrations. PGF2α increased cellular and extracellular cAMP at 1000-fold higher concentrations than PGE2 and did not affect cGMP levels.