EFFECTS OF GLUCOCORTICOIDS AND PROGESTERONE ON PROSTAGLANDIN-E2 AND LEUKOTRIENE B4 RELEASE BY HUMAN FETAL MEMBRANES AT TERM GESTATION

The present study was undertaken to evaluate the effects of the glucoc orticoid hormones betamethasone and hydrocortisone, and of progesteron e on the relative production of prostaglandin E2 (PGE2) and leukotrien e B4 (LTB4) by explants of human fetal membranes at term gestation in the absence of labor. Tissues (n = 7) were incubated either in the pre sence or in the absence of the above mentioned hormones. PGE2 and LTB4 were measured in culture medium by radioimmunoassays. Glucocorticoids and progesterone did not affect PGE2 output by tissues; however, they greatly stimulated LTB4 production. Moreover, both betamethasone and hydrocortisone significantly increased the ratio of LTB4 to PGE2 forma tion by tissues. These results suggest that glucocorticoid hormones an d progesterone might influence arachidonic acid metabolism in human fe tal membranes by stimulating the production of lipoxygenase rather tha n cyclooxygenase substances before the onset of labor.