A comparison of maternal serum levels of endothelial nitric oxide synthase, asymmetric dimethylarginine, and homocysteine in normal and preeclamptic pregnancies

BACKGROUND The aim of this study was to determine the maternal serum concentrations of eNOS, ADMA, and homocysteine in preeclamptic pregnancies. MATERIAL AND METHODS The study was carried out on 62 patients with pregnancy complicated by early onset and 53 patients with late onset preeclampsia. The control group consisted of 65 healthy normotensive pregnant patients. The serum eNOS, ADMA and homocysteine concentrations were determined using ELISA assays. RESULTS Our study revealed elevated levels of homocysteine and ADMA in the serum of women with preeclampsia. The highest levels were observed in patients with early onset preeclampsia, but the differences between both groups of preeclamptic patients with early and late onset of preeclampsia were not statistically significant. Both groups of preeclamptic women had slightly lower levels of maternal serum endothelial nitric oxide synthase than in normotensive pregnant women, but these differences were not statistically significant. CONCLUSIONS The higher levels of homocysteine and ADMA observed in patients with early onset preeclampsia may suggest that higher levels of maternal serum homocysteine and ADMA correlate with the severity, and may determine the earlier clinical onset of the disease. The elevated levels of ADMA and the unchanged levels of eNOS in preeclamptic pregnancies suggest that NO deficiency in this pregnancy disorder results not from a reduced level or activity of eNOS, but from elevated levels of ADMA, an endogenous eNOS inhibitor. The lowering of increased levels of homocysteine and ADMA may be helpful in therapy of vascular disturbances occurring in preeclampsia.