PURPOSE: To study the immunolocalization of the Bcl-2 protein in formalin-fixed placental tissue collected from uncomplicated term pregnancies. METHODS: A total of 19 human term placentas of 38-41 weeks' gestation, 11 obtained from spontaneous deliveries and eight from elective caesarean sections prior to labour were included. Sections were incubated with an antibody to the Bcl-2 protein and light microscopy was used to evaluate Bcl-2 staining. RESULTS: The anti-apoptotic Bcl-2 protein was expressed diffusely throughout the cytoplasm of the syncytiotrophoblast with much less intensive staining in cytotrophoblast and mesenchymal cells. Bcl-2 expression was reduced or lost in areas of syncytial sprouts. No differences in Bcl-2 staining were observed between placentas obtained after spontaneous deliveries and those collected before the onset of labour after elective caesarean section. CONCLUSION: Expression of the anti-apoptotic Bcl-2 protein in human term placenta does not seem to be influenced by parturition. Additionally, Bcl-2 expression might be an important factor in the regulation of apoptosis in the human trophoblast and thus in maintaining placental function during gestation.
PURPOSE: To study the immunolocalization of the Bcl-2 protein in formalin-fixed placental tissue collected from uncomplicated term pregnancies. METHODS: A total of 19 human term placentas of 38-41 weeks' gestation, 11 obtained from spontaneous deliveries and eight from elective caesarean sections prior to labour were included. Sections were incubated with an antibody to the Bcl-2 protein and light microscopy was used to evaluate Bcl-2 staining. RESULTS: The anti-apoptotic Bcl-2 protein was expressed diffusely throughout the cytoplasm of the syncytiotrophoblast with much less intensive staining in cytotrophoblast and mesenchymal cells. Bcl-2 expression was reduced or lost in areas of syncytial sprouts. No differences in Bcl-2 staining were observed between placentas obtained after spontaneous deliveries and those collected before the onset of labour after elective caesarean section. CONCLUSION: Expression of the anti-apoptotic Bcl-2 protein in human term placenta does not seem to be influenced by parturition. Additionally, Bcl-2 expression might be an important factor in the regulation of apoptosis in the human trophoblast and thus in maintaining placental function during gestation.