URINE BUT NOT PLASMA NITRIC-OXIDE METABOLITES ARE DECREASED IN WOMEN WITH PREECLAMPSIA

OBJECTIVE: Nitric oxide is a potent vasorelaxant produced by endotheli al cells. We tested the hypothesis that urinary and perhaps plasma nit ric oxide metabolites would be reduced in women with preeclampsia. STU DY DESIGN: Plasma and urine from 14 women meeting strict clinical crit eria for the diagnosis of preeclampsia and 20 normal nulliparous women were assayed for the stable metabolites of nitric oxide, nitrate and nitrite. RESULTS: There was no significant difference of plasma concen trations of nitrate and nitrite between women with preeclampsia and wo men with normal pregnancies (32.7 +/- 3.1 vs 25.8 +/- 2.4 mu mol/L). P lasma creatinine levels were elevated in women with preeclampsia (0.85 +/- 0.09 vs 0.66 +/- 0.02 mg/dl, p < 0.01), indicating a reduced glom erular filtration rate. Urine concentrations of nitrate and nitrite no rmalized by creatinine excretion were significantly lower in women wit h preeclampsia compared with normal pregnant women (0.37 +/- 0.06 vs 0 .69 +/- 0.11 mu mol of nitrite per milligram creatinine, p < 0.05). CO NCLUSIONS: Our study using concomitant measurement of plasma and urine nitrate and nitrite suggests a reduced production of nitric oxide in women with preeclampsia compared with normal pregnant women.