Study on the expression of angiotensin II (ANG II) receptor subtype 1 (AT1R) in the placenta of pregnancy-induced hypertension

Objective: To study the expression of angiotensin II (ANG II) receptor subtype I (AT(1)R) in the human placenta with pregnancy-induced hypertension (PIH). Methods: Immunohistochemistry was used to detect the expression of AT(1)R in placental tissues of 30 patients with PIH and 10 patients with normal pregnancies (control group). The PIH tissues were further divided into 3 groups: mild PIH group, moderate PIH group and severe PIH group. Each group consisted of 10 patients. A high-resolution pathological image analysis system (HPIAS-1000) was used to determine the quantity of AT(1)R expression. Results: The integral optical density and area of staining in the syncytiotrophoblast (STB) layer and villous endothelium of the placenta were significantly increased in PIH patients, in the moderate and severe PIH groups, as compared with the control group (P < 0.05), indicating that the expression of AT(1)R was highly increased in PIH. However, there was no significant difference between normal pregnancy and the mild PIH group (P > 0.05). Furthermore, statistically significant differences in AT(1)R expression were observed between mild, moderate and severe PIH groups (P < 0.05). Conclusion: The expression of AT(1)R is statistically significantly increased in the STB layer and villous endothelium of human placenta with PIH. Expression increases with the severity of the disease. Increased expression may be involved in the pathogenesis of PIH. (C) 2004 Elsevier Ltd. All rights reserved.