Expression of Heme Oxygenase-1?2 and Endothelin-1 in Human Placental Villus and Hheir Effect on Pregnancy-induced Hypertension

Objective:To study the expression of heme oxygenase-1(HO-1)?heme oxygenase-2(HO-2) and endothelin-1(ET-1) in the placental villus of pregnancy-induced hypertension (PIH) and their effect on pathogenesis of PIH. Methods: Immunohistochemistry was used to examine the expression of the HO-1?HO-2 and ET-1 in the placental villus tissues of 20 PIH patients and 20 women with normal term pregnancy (NTP). Immunohistochemistry image analysis systems was used to assess the average value of integral light density(LD) in the blood vessel and syncytiotrophoblast(STB) cells of the villus and microvillus as relative content of HO-1?HO-2 and ET-1. Results: Expression of HO-2 in the STB cells and blood vessel of villus and mirovillus was significantly lower in PIH group than in NTP group (P0.001), but expression of ET-1 in these location was higher in PIH group than in NTP group (P0.001). Expression of HO-1 in the STB cells was higher in NTP group than in PIH group (P0.001). The pregnant women's mean artery pressure (MAP) was inversely related to the relative content (LD) of HO-1 and HO-2, but positively related to the relative content (LD) of ET-1 in the STB cells of placental villus and microvillus. Conclusions: The decrease of HO and increase of ET-1 in the placenta of PIH patients may be one of the important mechanisms for the onset of PIH.