Immunohistochemical Localization of S‐100 Protein in the Pig Pituitary Gland

Abstract

Immunohistochemical localization of S-100 protein was studied in anterior, intermediate and posterior lobe of the pig pituitary gland. Two immunopositive cells for S-100 protein were identified: the folliculo-stellate cells (FSc) in the glandular lobes and the pituicytes in the neural lobe. In the anterior lobe, immunoreactive folliculo-stellate cells were scattered among secretory cells. In the area where the secretory cells form strands and follicle-like groups the positive cells were concentrated in groups. In the intermediate lobe, S-100 protein-positive cells were located sparsely among secretory cells and next to secretory follicles and the pituitary cleft. These FSc were more voluminous and displayed fewer cytoplasmic processes. In the neurohypophysis, positive reaction for S-100 protein was seen in the pituicytes. These cells were distributed singly or concentrated in groups. The distribution, and morphologic characteristics of the FSc in the glandular lobes and the pituicytes in the neural lobe in the pig indicate different origin of both S-100 protein-positive cells.

Pituitary Pars Intermedia of Male Viscacha<i> (Lagostomus maximus maximus)</i>: A Morphometric Study of Seasonal and Age-Related Changes in Immunohistochemistry

“…The pituitary FSC, also called follicular, stellate, agranulated or glial-like cells, have been reported in mammalian [Soji et al, 1994;Lebaili et al, 1999;Cardin et al, 2000;Inoue et al, 2002;Mabuchi et al, 2004;Marettová and Maretta, 2004;Shirasawa et al, 2004] and non-mammalian species [De Rijk et al, 1991;Chowdhury and Yoshimura, 2002]. At present, there is no agreement in the literature in relation to the exact function and embryological origin of these cells.…”

“…In different mammalian species, the FSC of pituitary PI were immunostained with anti-S-100, anti-GFAP and/ or anti-vimentin [Stoeckel et al, 1981;Sands and Chronwall, 1996;Méndez et al, 1998;Lebaili et al, 1999;Cardin et al, 2000;Marettová and Maretta, 2004]. The typical expression of S-100 proteins [Nakajima et al, 1980] and GFAP [Velasco et al, 1982] in the FSC suggested that they have a neuroectodermic origin [Marin et al, 1989;Renner et al, 1998].…”

“…In pituitary PI, they were chromophobic, stellate in shape with cytoplasmic processes [Takeuchi, 2001]. The FSC of the pituitary gland have been described in humans [Morris and Hitchcock, 1985;Coates and Doniach, 1988;Redecker and Fechner, 1989], rats [Nakajima et al, 1980;Shirasawa et al, 1983;Tsuchida et al, 1991;, pigs [Marettová and Maretta, 2004], mink [Cardin et al, 2000], dogs and horses [Méndez et al, 1998] using the anti-S-100 protein antiserum. A subpopulation of these cells expressed the glial fibrillary acidic protein (GFAP) whose presence varied under numerous physiological conditions, probably indicating a regulatory function Sands and Chronwall, 1996].…”

Folliculostellate cells in pituitary pars distalis of male viscacha: immunohistochemical, morphometric and ultrastructural study

“…In different mammalian species, FSC have been shown to exhibit both nuclear and cytoplasmic, 42 only nuclear 43 or only cytoplasmic 9 immunostaining for S-100 protein. In addition, some authors have reported that they were immunostained with anti-GFAP 1,7,11,44 and anti-vimentin.…”

“…2–5 FSC have been found lining the lumen of follicles scattered throughout the pituitary pars distalis. 5–9 The FSC have been studied using the antibody against S-100 protein, in both mammalian 6–12 and non-mammalian species. 3,4,13 In addition, some authors have reported in human, 11 cat, rat and rabbit 14 and mink 7 that FSC were immunostained with anti-glial fibrillary acidic protein (GFAP) and anti-vimentin.…”