PLASMA FROM WOMEN WITH PREECLAMPSIA INCREASES ENDOTHELIAL-CELL NITRIC-OXIDE PRODUCTION

In preeclampsia, a factor in the maternal circulation alters endotheli al function via a reduction in nitric oxide synthesis. We measured the in vitro effects of 2% plasma from women with preeclampsia, compared with 2% plasma from normotensive pregnant women, on cultured endotheli al cell nitrite production and nitric oxide synthase activity. On find ing differential effects, we measured the effects on cellular viabilit y (assessed by lactate dehydrogenase levels) and performed a time cour se study. Endothelial cell nitrite production was found to be higher a fter exposure to plasma from the preeclamptic group than the normotens ive pregnant group. The effects of long-term exposure (120 hours) were similar to those of short-term exposure (24 hours). In addition, nitr ic oxide synthase activity was significantly greater after exposure to preeclamptic plasma than after exposure to normotensive pregnant plas ma. No differential effect on cellular viability was found. Contrary t o our hypothesis, exposure of endothelial cells to preeclamptic plasma resulted in increased nitric oxide production and nitric oxide syntha se activity.