Steroid synthetic and prostaglandin metabolizing activity is present in different cell populations from human fetal membranes and decidua.

We examined whether different cell subpopulations from human fetal membranes and decidua produce steroids (estrone and progesterone) and metabolize prostaglandins (prostaglandin F2 alpha to 13, 14-dihydro-15-keto-prostaglandin F2 alpha and if these changed with labor. Amnion, chorion, and decidua were obtained at elective cesarean section at term or at spontaneous labor. Cells were dispersed with collagenase and separated by density on discontinuous Percoll gradients. At cesarean section there was a major broad band of cells from amnion and chorion. This band contained most of the estrone sulfatase (estrone sulfate to estrone) activity. The 3 beta-hydroxysteroid dehydrogenase (pregnenolone to progesterone conversion) and prostaglandin F2 alpha metabolizing activities were present in these cells and those that migrated at greater Percoll densities. Amnion and chorion obtained after spontaneous labor had two major bands of cells. Estrone sulfatase was present in cells from both hands, whereas progesterone output from pregnenolone and prostaglandin F2 alpha metabolism predominated in the second band of cells with greater density. This pattern was particularly apparent in chorion. Dispersed cells from decidua tended to migrate throughout the gradient. In general, estrone sulfate to estrone conversion predominated in lighter cells whereas progesterone output from pregnenolone and prostaglandin F2 alpha metabolism predominated in cells of greater density. The output of progesterone from pregnenolone was significantly lower in cell preparations from chorion and decidua at spontaneous labor compared with cesarean section. We conclude that human amnion, chorion, and decidua contain distinct cell subpopulations based on Percoll migration and that in the membranes these change between cesarean section and spontaneous labor. Partial separation of estrone sulfatase from 3 beta-hydroxysteroid dehydrogenase and prostaglandin F2 alpha metabolizing activities has been demonstrated, which raises the possibility of paracrine interactions in vivo.