Immunohistochemical location of HPL, SP1 and beta-HCG in normal placentas of varying gestational age.
Sixty-four placentas at various gestational ages were examined by immunohistochemical stains for HPL, SP1 and beta-HCG according to a modified PAP method (Sternberger 1970). Syncytiotrophoblast cell layer was identified as the main site of synthesis. Extravillous immunohistochemical reactions for HPL and SP1 (but not for beta-HCG) were found in X-cells of the basal plate and in the intervillous trophoblast islands. These cell types would thus seem to be derived from trophoblast. Hofbauer-cells of villous connective tissue stained specifically for beta-HCG apparently because of HCG phagocytosis. The intensity of staining for HPL, SP1 and beta-HCG was evaluated semiquantitatively in the syncytiotrophoblast cell layer at various gestational weeks. The maximum of staining for beta-HCG was found in the uniform syncytiotrophoblast layer of immature intermediate villi in early pregnancy (7-14 weeks), HPL and SP1 had their peak of staining reaction at 32-36 weeks of gestation. Increasing maturation results in a subspecialisation of the villous surface: epithelial plates (allowing feto maternal exchange) and nucleated portions of syncytiotrophoblast (which are the main site of hormone production and endocrine activity).
D006063:Chorionic Gonadotropin / Q000032:analysis*; D002824:Chorionic Villi / Q000378:metabolism; D005260:Female; D006651:Histocytochemistry; D006801:Humans; D007124:Immunoenzyme Techniques; D010920:Placenta / Q000378:metabolism*; D010928:Placental Lactogen / Q000032:analysis*; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000032:analysis*; D011268:Pregnancy-Specific beta 1-Glycoproteins / Q000032:analysis*; D013194:Staining and Labeling; D013997:Time Factors; D014327:Trophoblasts / Q000378:metabolism
D006063:Chorionic Gonadotropin; D011257:Pregnancy Proteins; D011268:Pregnancy-Specific beta 1-Glycoproteins; D010928:Placental Lactogen