RESUMEN
OBJECTIVE: The aim of this study was to measure circulating levels of nitric oxide metabolites (nitrites) in the uteroplacental, fetoplacental, and peripheral circulation in women with normal pregnancy and preeclampsia. METHODS: Two groups of pregnant women were included : 20 patients with preeclampsia and 18 normotensive women. At cesarean, blood samples were taken from the antecubital vein and uterine vein draining the placental site before delivery of the baby, and the umbilical vein after delivery of the baby. Plasma nitric oxide concentrations were determined with the Griess reaction by measuring combined oxidation products of nitric oxide, plasma nitrite and nitrate after reduction with nitrate reductase. RESULTS: Significantly higher serum nitrite concentrations were found in umbilical (46.53+/-22.01 vs. 17.51+/-7.43 M/L, p<0.05), uterine (51.78+/-14.19 vs. 21.23+/-11.6 M/L, p<0.05) and antecubital (66.41+/-20.87 vs. 21.26+/-9.54 M/L, p<0.05) venous plasma in the preeclamptic group compared with the control group. CONCLUSION: We observe higher levels of nitirc oxide metabolites in the uteroplacental, fetoplacental, and peripheral circulation in women with preeclampsia than in normal pregnancy. These results support the hypothesis that increased nitric oxide production may be a compensatory response to improve blood flow and offset the pathologic effects of preeclampsia.