Changes in nitric oxide production in preeclampsia

Lee, In Sik; Yoo, Hye Kyung; Jung, Bok Kyung; Won, Hye Sung; Lee, Pil Ryang; Kim, Ahm; Nam, Joo Hyun

Abstract

OBJECTIVE
To determine the changes of nitric oxide production in preeclampsia, the concentration of nitric oxide metabolite, nitrite, was measured in umbilical vein after perfusing plasma from normal pregnant women and preeclamptic pregnant women. MATERIAL AND METHOD: 15 normal and 15 preeclamptic umbilical cords were obtained at the time of cesarean section. Two pieces of umbilical cord in equal length(20 cm in length) were prepared from each umbilical cord. Two pieces of umbilical cord were connected in parallel in a perfusion chamber. One piece of umbilical cord was perfused sequentially for 20-minutes' interval with the perfusates in the order of cord buffer, cord buffer including 15% normal pregnant serum, 15% normal pregnant serum with histamine(10-5mol/L), 15% normal pregnant serum with calcium ionophore A23187(5 mol/L) and the other one was perfused exactly same way using 15% preeclamptic serum instead of 15% normal pregnant serum. All the perfusates used were gassed with 95% O2 and 5% CO2 and warmed to 37degree C. Perfusates were collected in eppendorf tube and freezed at -70degree C until assayed. NO was measured by means of Greiss reaction. one way ANOVA and paired t-test were used where appropriate and p-value < 0.05 was considered significant.
RESULTS
NO production in normal umbilical cords was not different regardless of perfusate. Although adding histamine and calcium ionophore, the NO production was slightly increased but statistically not significant in both groups. NO production in preeclamtic umbilical cords was significantly increased with 15% preclamptic serum(15% normal serum vs. 15% preeclamptic serum; 0.060+/-0.016microgram/ml/min vs 0.075+/-0.014microgram/ml/min, p<0.05).
CONCLUSION
The preeclamptic sera may not affect the production of NO in the human umbilical vein endothelial cells. The biologic significance of increased NO production in preeclamptic umbilical cord with perfusing preeclamptic serum is unknown, but it might be compensation for the vasoconstriction of preeclampsia.