Adrenomedullin mRNA expression in placenta of preeclamptic women

Abstract

Summary Introduction: Adrenomedullin (ADM) is indicated to be a biologically active polypeptide released by endothelium with strong hypotensive, long-acting vasodilatator properties. It is suggested that development of preeclampsia is partly related to decreased ADM influence on blood vessels. Aim: The purpose of this study was to evaluate the adrenomedullin mRNA expression in placenta of preeclamptic women and additionally to assess the correlation between ADM mRNA expression and -1984A>G ADM gene polymorphism. Material and methods: 26 preeclamptic (PE), 20 with gestational hypertension (GH) and 43 normotensive healthy pregnant women have been involved into the study. The placenta samples were collected instantly after delivery from the central part of maternal side. The ADM gene expression was measured with the real-time polymerase chain reaction (rt-PCR). The results were standardized according to the reference glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene. The –1984A>G ADM gene polymorphism was determined by PCR/RFLP assay. Results: Lower expression of ADM mRNA in PE group (0.881+/-0.254 vs. 1.039+/-0.391 in controls, ns) has been investigated. In PE group the placental ADM mRNA expression was slightly higher at women carrying AA genotype (0.890+/-0.263 vs. 0.842+/-0.231, ns). In the control group higher placental ADM mRNA expression in women with AG+GG genotype of –1984A>G ADM gene polymorphism (1.249+/-0.431) in comparison to women carrying AA genotype (1.036+/-0.356, ns) was observed. The study also revealed negative correlation between placental ADM mRNA expression and systolic blood pressure in hypertensive pregnant women (p=0.020). Conclusion: Reduced mRNA expression for ADM in the placenta connected with reverse correlation of systolic blood pressure in preeclamptic women suggests the significant role of disturbances in placental secretion of ADM in etiology of preeclampsia.