Postnatal development of the interstitial cells (palisade cells) of the pars intermedia in the cat pituitary gland. An immunocytochemical and ultrastructural study.
The postnatal development of the interstitial agranulated cells (so-called palisade cells) of the pars intermedia in the cat was investigated immunocytochemically and at the ultrastructural level. Since the first postnatal days, a strong vimentin immunoreactivity and a weaker S-100 protein immunoreactivity were detected in the marginal cells lining the pituitary cleft and in the interstitial bipolar cells located within the pars intermedia. No glial fibrillary acidic protein cells have been found in the pars intermedia of any of the animals studied. This immunocytochemical pattern was maintained throughout the postnatal development. Ultrastructurally these cells showed a vast number of cytoplasmic filaments and well-developed junctional complexes. Secretory granules were never seen. In older animals they lined microcavities and microchannels where they project microvilli and present pinocytotic vesicles on their apical surface. No transitional forms between these cells and granulated secretory cells were found. There is a large number of axons and synaptic endings in contact with the granulated secretory cells. From our findings we guess that palisade cells are not a glial derivative, but they may share a common origin with secretory granulated cells.
Marín
J F
JF
Department of Histology, Faculty of Medicine, University Complutense, Madrid, Spain.
Boya
J
J
D000367:Age Factors; D000818:Animals; D002415:Cats; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D007150:Immunohistochemistry; D008297:Male; D016900:Neurofilament Proteins / Q000032:analysis; D010902:Pituitary Gland / Q000737:chemistry / Q000166:cytology* / Q000648:ultrastructure; D009418:S100 Proteins / Q000032:analysis; D014746:Vimentin / Q000032:analysis
D005904:Glial Fibrillary Acidic Protein; D016900:Neurofilament Proteins; D009418:S100 Proteins; D014746:Vimentin