Expression of endothelial nitric oxide synthase traffic inducer in the placentas of women with pre-eclampsia

Abstract

Objective To investigate the expression of endothelial nitric oxide synthase traffic inducer (NOSTRIN) in the placenta of women with pre-eclampsia (PE) and discuss its role in the pathogenesis of PE. Methods Western blot analysis was used to detect the expression of NOSTRIN and endothelial nitric oxide synthase (eNOS). The activity of eNOS in placental tissue was assayed by spectrophotometry. Serum and placental NO 2/NO 3, the stable metabolic end product of NO, was measured using nitrate reductase. Results Western blot analysis showed that the protein level of NOSTRIN was significantly higher in women with PE than in the control group ( P<0.01). However, no significant difference between groups was observed in the expression of placental eNOS ( P>0.05). The activity of eNOS was significantly decreased in women with PE (13.727±3.58 U/mg) compared with the control group (21.69±3.84 U/mg) ( P<0.01). The placental levels of NO 2/NO 3 were significantly lower in women with PE (27.53±8.51 μmol/mg) than in the control group (44.38±9.59 μmol/mg) ( P<0.01). The levels of serum NO 2/NO 3 were significantly lower in women with PE (48.56±8.49 μmol/L) than in the control group (65.37±9.61 μmol/L) ( P<0.01). A significant negative correlation existed between the expression of NOSTRIN protein and the activity of eNOS in the placental tissues of women with PE ( r=−0.57, P<0.01). Conclusion The level of NOSTRIN expression in the placental tissues of women with PE is increased and is negatively correlated with the activity of eNOS—which may play an important role in the pathogenesis of PE.