Prostaglandin production by human term placentas in vitro

The release of PGs increases with increasing incubation time and the main PG produced is different in different tissues. This could implicate the presence of an inhibitory factor in vivo. PGE release is the same in patients in labor and not in labor, and this PG is mainly produced by the villi. Villi, membranes and decidua in tissue cultures from patients not in labor release more PGF than patients in labor, the difference for the decidual tissue being strikingly large. Conversion of labelled arachidonic acid by pieces of term placenta from women in labor during short-term incubations was mainly to PGE2 and its metabolites and PGD2.