Clinical Investigation

Nitric Oxide As A Mediator On Severe Preeclamptia

  • Taner Toprak
  • İsmail Evren
  • Erbil Çakar
  • Necdet Süer

Turk J Obstet Gynecol 2010;7(3):196-201


Recent studies dealing with the pathophysiology of preeclampsia focus mainly on vascular resistance, endothelial damage and mediators regulating vascular tonus. The aim of this study was to evaluate the role of nitric oxide, which is a vasoactive mediator, in preeclampsia. We measured correlation between nitric oxide synthesis and maternal arterial blood pressure were evaluated by measuring metabolites of nitric oxide in maternal plasma and urine.

Patients and Method:

Twenty-three pregnant women admitted for prenatal care to our antenatal policlinic with a diagnosis of severe preeclampsia after 28 weeks of gestation were included in this study. Thirty normotensive patients served as controls. Maternal serum and urine kreatinin, uric acid, nitrat and nitrit concentrations in both groups were compared.


HELLP syndrome was diagnosed in three patients with preeclampsia. Maternal serum (1,7±0,6 ve 1,3±0,2 mg/dl, P=0,01) and urine (142±57 ve 106±39 mg/dl, P=0,03) kraetinin and maternal serum uric acid (8.9±2 ve 3,7±1 mg/dl, P<0.001) concentrations were significantly higher in patients with preeclampsia. Although plasma nitrit/nitrat concentrations in patients with preeclampsia were significantly higher (26.5±7.6 ve 20.0±6.3 mg/dl, P = 0.001),they were comparable in maternal urine. (51.9±11 ve 55.7±9.9 mg/dl, P>0.05).


This study does not support the hypothesis that the nitric oxide synthesis is decreased in patients with preeclampsia. Furthermore, it clarifies that pathophysiological changes of preeclampsia might not be explained with changes of a single mediator. There is a need for more larger studies explicating the role of nitric oxide in preeclampsia.

Keywords: Nitric oxide, Preeclampsia, Pregnancy, Hypertension