Prostaglandins have no effect on spontaneous and gonadotrophin-releasing hormone stimulated luteinizing hormone release in cultured rat pituitary cells.

Primary cultures of pituitary cells from adult female rats were exposed to increasing concentrations (10(-13) to 10(-6)M) of selected prostaglandins (PGE2, PGF2 alpha, PGI2, 6-keto-PGF1 alpha, and sulproston). The release of luteinizing hormone (LH) by the pituicytes was monitored. In a second series of experiments, pituitary cells were treated with prostaglandins as described above and additionally challenged with a submaximal stimulus of gonadotrophin-releasing hormone (GnRH; 10(-9) M). The spontaneous LH-release in all prostaglandin treated cultures did not differ from the controls. When stimulated with 10(-9) M GnRH, the LH-release increased approx. six-fold in all cultures, with no difference between prostaglandin treated cells and the respective controls. Thus, the prostaglandins tested - at least at concentrations less than or equal to 10(-6) M - have neither a direct positive or negative effect on pituitary LH-release, nor do they enhance or decrease the LH-releasing effect of GnRH. These prostaglandins are probably not involved in the cellular regulation of LH-release by the pituicyte.