VEGF immunoexpression in the pituitaries of pregnant women

Abstract

Previous studies showed that in pregnancy the pituitary enlarges and increases in weight due to lactotroph hyperplasia. We demonstrated that in pituitaries of pregnant women, microvessel density is significantly increased compared to those of age– matched non pregnant women. Vascular endothelial growth factor (VEGF) stimulates new vessel formation in several tissues and neoplasms. The aim of the present study was to reveal whether VEGF is involved in the causation of increased vascularity in the pituitaries of pregnant women. We assessed VEGF immunoexpression in 20 autopsy obtained pituitaries of pregnant women and compared the results with 20 controls. Slides were immunostained for VEGF and pituitary hormones using the streptavidin‐biotin‐peroxidase complex method. VEGF immunoexpression was evaluated in 10 random high‐power fields using an image analyzer and the results compared by chi‐square or Fisher exact tests. Immunoexpression of VEGF was not increased in the adenohypophyses of pregnant women compared with the controls indicating that VEGF plays no major role in the causation of increased vascularity. The cause remains to be investigated.