Korean J Obstet Gynecol.
1999 May;42(5):990-996.
Effect of Plasma from Preeclamptic Women on the Nitric Oxide Production in Cultured Human Umbilical Vein Endothelial Cells
Abstract
OBJECTIVE
To evaluate whether preeclamptic plasma changes nitric oxide[NO] production in cultured human umbilical vein endothelial cells.
MATERIALS AND METHODS
Plasma were collected from 10 severe preeclamptic women and 10 gestational age-matched normal pregnancies. Endothelial cells were isolated from umbilical cord veins of patients receiving elective cesarean section at term. Various concentrations of plasma[2% and 20%] were added to the cultured endothelial cells. After 24 hours` incubation, nitrite concentrations in the cell media were determined with the Greiss assay. Nitrite concentrations after exposure to the preeclamptic plasma were compared with those to the normal pregnancies. Wilcoxon signed rank test and Mann-Whitney U test were used for statistical analysis.
RESULTS
Nitrite production exposed to the plasma from preeclamptic patients was increased significantly as the concentration of plasma was increased[plasma free media; median 0.012microgram/ml range 0.001-0.022microgram/ml, 2%; median 0.027microgram/ml range 0.006-0.095microgram/ml, 20%; median 0.067% range 0.016-0.252microgram/ml][p<0.005]. In contrast, 2% plasma of normal pregnancies did not increase nitrite production. However, nitrite production exposed to the 20% plasma from normal pregnancies was significantly increased comparing with that of 2% plasma[2%; median 0.017microgram/ml range 0.008-0.021microgram/ml, 20%; median 0.027% range 0.006-0.068microgram/ml][p<0.05]. Within the same concentrations, preeclamptic plasma showed significantly higher nitrite productions[mean+/-standard error of mean] than normal pregnant plasma[2%; 0.036+/-0.009microgram/ml vs 0.016+/-0.001microgram/ml, p<0.05][20%; 0.099+/-0.024microgram/ml vs 0.028+/-0.007microgram/ml, p<0.005].
CONCLUSION
These data suggest that preeclamptic plasma may contain [a] certain factor[s] which stimulate[s] NO production in vascular endothelial cells. This implies that vascular endothelial NO production mat be a compensatory mechanism for the vasoconstriction in preeclampsia.