Study On Expression Of Nitric Oxide Synthase In Placenta And Umbilical Cord Of Fetal Growth Restriction

Objectives:To investigate the expression of iNOS and eNOS in the human placenta and umbilical cord and the expression of eNOS mRNA in the human placenta obtained from fetal growth restriction(FGR),in order to explore the role of iNOS and eNOS in the pothogenesis of FGR.Methods:1 Samples of placenta and umbilical cord(control group n=15,FGR group n=15) were collected.The staining intensity and distribution of iNOS and eNOS in these samples were analysed by image analysis technique.2 Samples of placenta(control group n=14,FGR group n=12) were collected,the expression of eNOS mRNA in these samples was analysed by the method of RT-PCR.Results:1 iNOS was localized in the placental trophoblasts,Hofbauer cells and the villous capillary endothelium,as well as in the endothelial cells and smooth muscle of umbilical arteries and veins.In trophoblasts,the staining intensity of iNOS in FGR group was significantly higher than that of control group(P＜0.01).No significant difference was found in other two groups. 2 eNOS was localized in the placental trophoblasts and the villous capillary endothelium,eNOS staining could be seen in terminal villous vessels and stem villous vessels,and also in the endothelial cells of umbilical arteries and veins.In umbilical vein,the staining intensity of eNOS in FGR group was statistically significantly higher than that of control group(P＜0.01).No significant difference was found in other two groups.3 The expression of eNOS mRNA was not significantly different from the control group.Conclutions:1 The obviously increased expression intensity of iNOS in placenta of FGR indicates that FGR is a result of hypoxia/ischemia.2 The increased eNOS expression in the umbilical vein may be an adaptive response to the increased resistance and hypoxic state of the fetoplacental circulation.