Prostaglandins Do Not Affect Steroidogenesis and Are Not Being Produced in Response to oLH in Chicken Granulosa Cells

Abstract

The aim of this study was twofold. First, to evaluate the effects of PGE₂ and PGF_2α on basal and oLH-promoted progesterone release in vitro and in vivo and second, to study the effects of oLH on the production of PGE, PGF, and 6-keto-PGF_1α in cultured chicken granulosa cells. A radioimmunoassay was developed to measure the latter prostaglandin, a stable product of prostacyclin (PGI₂). We found that neither prostaglandins affected progesterone release in granulosa cells or the concentration of this steroid in the plasma. With the exception of high doses of PGE₂ (1 and 5 µg/ml), which partially suppressed oLH-stimulated progesterone production in vitro, there was no effect in vitro or in vivo on gonadotropin-induced steroidogenesis. Moreover, oLH (0.1 and 5 µg/ml) failed to stimulate the production of PGE, PGF, or 6-keto-PGF_1α in granulosa cells up to 7 h of incubation. These results indicate that the above prostaglandins are not involved in LH-promoted steroidogenesis in the domestic fowl either directly or as mediators/modulators.