-transparent.png){kind=logo}
Forty autopsy pituitaries were studied to elucidate the histology, immunocytology and ultrastructure of pars tuberalis in subjects with normal and abnormal endocrine homeostasis. Pars tuberalis consisted mainly of gonadotrophs interspersed with few corticotrophs and thyrotrophs, histologically resembling those of pars distalis. Somatotrophs and lactotrophs were not identified. There were no histologic differences attributable to age or sex. In cases of glucocorticoid excess, pars tuberalis corticotrophs showed Crooke's hyalinization. Following castration or hypophysectomy, pars tuberalis gonadotrophs exhibited more intense immunostaining for FSH and LH than did normals. Ultrastructural analysis revealed gonadotrophs and corticotrophs showing no evidence of active secretion; immunoelectron microscopy demonstrated FSH, LH and ACTH in secretory granules. By light microscopy, squamous nests, often identified in pars tuberalis, were positive for immunoreactive keratin; cells at their periphery contained FSH, LH or ACTH, indicating derivation of nests by squamous metaplasia from gonadotrophs and corticotrophs. By electron microscopy, clusters of epithelial cells containing desmosomes and tonofilaments were surrounded by granulated gonadotrophs. Human pars tuberalis cells represent mainly a subpopulation of gonadotrophs possessing all organelles required for synthesis and storage of hormones but showing ultrastructural features of functional inactivity; the reasons for this inactivity and for the formation of squamous nests remain unexplained.
S L Asa, and
K Kovacs, and
J M Bilbao
September 1993,
Human pathology,
S L Asa, and
K Kovacs, and
J M Bilbao
January 1982,
Fertility and sterility,
S L Asa, and
K Kovacs, and
J M Bilbao
January 2002,
Ultrastructural pathology,
S L Asa, and
K Kovacs, and
J M Bilbao
May 2005,
The anatomical record. Part A, Discoveries in molecular, cellular, and evolutionary biology,
S L Asa, and
K Kovacs, and
J M Bilbao
January 1990,
Acta neuropathologica,
S L Asa, and
K Kovacs, and
J M Bilbao
December 1978,
Cell and tissue research,
S L Asa, and
K Kovacs, and
J M Bilbao
January 1999,
Ultrastructural pathology,
S L Asa, and
K Kovacs, and
J M Bilbao
August 1977,
Cell and tissue research,
S L Asa, and
K Kovacs, and
J M Bilbao
January 1989,
Acta anatomica,
S L Asa, and
K Kovacs, and
J M Bilbao
December 1970,
Comptes rendus hebdomadaires des seances de l'Academie des sciences. Serie D: Sciences naturelles,
