Nitric oxide in human fetal membranes at term gestation: effect on prostaglandin E2 release

To examine the in vitro release of nitric oxide (NO) by human fetal membranes at term gestation and to investigate whether NO could stimulate prostaglandin E2 (PGE2) release by these tissues.

Explants of fetal membranes (n = 17) were incubated either in the presence of sodium nitroprusside (NP), or L-Arginine (L-Arg), or bacterial lipopolysaccharide (LPS), or in the absence of the above substances (controls). NO and PGE2 concentrations in culture medium were assayed by the Griess reaction and radioimmunoassay, respectively.

Fetal membranes spontaneously released NO in culture medium; incubation with NP increased the production of both NO and PGE2. L-Arg and LPS enhanced PGE2 output by tissues but did not influence NO production.

An NO-generating activity might be present in human fetal membranes. NO stimulates PGE2 release by these tissues.