Identification of gonadotropic cells in the human pituitary by immunoperoxidase technique

Using specific antibodies against the beta-subunits of human LH and FSH, the pituitary cells which produce the two gonadotropins have been localized in the human pituitary by an immunoperoxidase technique. In serial semi-thin sections (2 mum), it was clearly shown that about 90% of gonadotropic cells contained both FSH and LH, whereas the remaining 10% of gonadotrophs were positive only for FSH. At the ultrastructural level, the gonadotrophs containing both LH and FSH were characterized by the presen-e of two types of secretory granules: the smaller ones which whowed a strong immunohistochemical reaction and the larger ones which generally presented a weaker reaction.