Endothelial nitric oxide synthase expression in gestational trophoblastic diseases

Objective: Nitric oxide is thought to play a role in the regulation of trophoblast activity. The aim of this study was to compare endothelial nitric oxide synthase expression in tissue samples taken from gestational trophoblastic diseases and placentas of normal pregnancies. Methods: The expression of endothelial nitric oxide synthase was tested in formalin-fixed, paraffin-embedded tissues from specimens including 8 first trimester placentas, 3 partial hydatidiform moles, 20 complete hydatidiform moles, 2 invasive moles, and 5 choriocarcinomas. The expression of antibody was scored by a semiquantitative scale to define staining intensity. Results: The first trimester placentas showed moderate expression in the villous. Gestational trophoblastic diseases displayed strong to very strong endothelial nitric oxide synthase expression in the syncytiotrophoblast, villous, and proliferating mononuclear trophoblasts. Conclusions: Endothelial nitric oxide synthase expression seems to have a strong correlation with proliferation of trophoblastic cells, in gestational trophoblastic diseases and in normal pregnancy. Copyright © 2010 by IGCS and ESGO