title: Transient expression of S-100 by melanotropes of the rat pituitary intermediate lobe during development.
abstract: S-100, an acidic calcium-binding protein, is co-localized with vimentin in glial-like cells in the adult rat pituitary intermediate lobe. S-100 and melanotrope markers were not co-localized in the adult. During development, S-100 and vimentin were not co-localized but appeared in cells with different morphological characteristics. S-100 was co-localized with POMC mRNA and beta-endorphin during prenatal time and the first three postnatal weeks. This was demonstrated by double-label immunohistochemistry, using combinations of antisera against S-100, vimentin and beta-endorphin, and in situ hybridization histochemistry for POMC mRNA combined with immunohistochemistry for S-100. In the second and third weeks of postnatal development, S-100 was observed in fewer melanotropes and more frequently in stellate cells, which also expressed vimentin. Thus, S-100 appeared to be transiently expressed in melanotropes during prenatal and early postnatal development. S-100 serves as a neurotrophic and glial maturation factor in the CNS. Since S-100 expression in melanotropes coincides with the onset of dopaminergic innervation and morphological changes in glial-like cells of the lobe, it could have similar functions in the rat pituitary intermediate lobe.
authors.affiliation: School of Biological Sciences, University of Missouri-Kansas City 64108, USA.
authors.forename: S A
authors.initials: SA
authors.lastname: Sands
authors.forename: K A
authors.initials: KA
authors.lastname: Gary
authors.forename: B M
authors.initials: BM
authors.lastname: Chronwall
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001483:Base Sequence; D003238:Connective Tissue / Q000378:metabolism; D003239:Connective Tissue Cells; D005314:Embryonic and Fetal Development / Q000502:physiology; D005865:Gestational Age; D007150:Immunohistochemistry; D008547:Melanophores / Q000166:cytology / Q000378:metabolism*; D008969:Molecular Sequence Data; D009457:Neuroglia / Q000378:metabolism*; D010902:Pituitary Gland / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D009418:S100 Proteins / Q000032:analysis / Q000096:biosynthesis*; D013997:Time Factors
chemical_list: D009418:S100 Proteins