Somatostatin in cytotrophoblast of the immature human placenta: localization by immunoperoxidase cytochemistry.

Using the technique of immunoperoxidase cytochemistry, we have demonstrated the presence of immunoreactive somatostatin in the cytotrophoblast. This is contrasted by the immunocytochemical staining of human placental lactogen in the syncytotrophoblast in the adjacent section of the villus tissue of the immature human placenta. It is considered that the somatostatin may be involved in the secretion of human placental lactogen within the two layers of trophoblastic cells.