[Immunohistochemistry of the basal plate of the full-term human placenta : x cell characterization with anti-hCS and anti-hCG sera labeled with peroxidase].

Immunohistochemical reaction with peroxydase has been applied in human full-term placentas for the detection of the cells of the basal plate containing hCG and hCS. This reaction was positive with both optic and electronic microscopes in the so-called X cells. This fact seems to confirm the trophoblastic origin and the endocrine function of the cells.