PLASMA NITRIC-OXIDE METABOLITE LEVELS ARE DECREASED IN PREECLAMPTIC WOMEN COMPLICATED WITH FETAL DISTRESS

To investigate the possible role of impairment of the maternal vascula r nitric oxide (NO)-soluble guanylate cyclase system in the maintenanc e of placental oxygen supply to the fetus in pre-eclampsia, maternal p lasma levels of nitric oxide metabolites (nitrate and nitrite, i.e. NO x), atrial natriuretic peptide (ANP) and brain natriuretic peptide (BN P), and guanosine 3',5'-cyclic phosphate (cGMP) were measured using Gr iess reagent, specific immunoradiometric assays (IRMA) and specific ra dioimmunoassay (RIA), respectively. The subjects were ten normal non-p regnant women, and 91 normal pregnant women, nine pre-eclamptic women without fetal distress a nd six pre-eclamptic women with fetal distres s.In the pre-eclamptic women with fetal distress, plasma NOx levels we re significantly (p < 0.05) lower than those in gestational age-matche d normotensive pregnant women, but not in those without fetal distress . Plasma ANP and BNP levels in the pre-eclamptic pregnant women with f etal distress were significantly higher than those in gestational age- matched normotensive pregnant women. No significant differences were o bserved among plasma levels of cGMP, the common second messenger of bo th soluble and particulate guanylate cyclases. The present findings su ggest that endothelial NO synthase (eNOS) is impaired in women whose p regnancies are complicated with pre-eclampsia and fetal distress.