The expression of endothelial nitric oxide synthase traffic inducer (NOSTRIN) was examined in the umbilical vessels of the patients with pre-eclampsia (PE) to explore its possible role in the pathogenesis of PE. The NOSTRIN mRNA in umbilical tissues was determined by RT-PCR. The eNOS activity in umbilical vessels was spectrophotometrically detected. NO2-/NO3-, the stable metabolic end products of NO, was measured by using nitrate reductase. RT-PCR showed that the expression level of NOSTRIN was significantly higher in women with PE than in the normal group (P<0.01). The activity of eNOS was significantly decreased in PE group [(12.83+/-3.61) U/mg] than in normal group [(21.72+/-3.83) U/mg] (P<0.01). The level of NO2-/NO3- in PE patients (27.53+/-7.48) micromol/mg was significantly lower than that of normal group (54.27+/-9.53) micromol/mg (P<0.01). The significant negative correlation existed between the expression of NOSTRIN and the activity of eNOS in umbilical vessels of women with PE (r=-0.58, P<0.01). It was concluded that the level of NOSTRIN expression was increased in umbilical vessel of women with PE, indicating that it may be involved in the pathogenesis of PE.