Summary
In the pituitary gland of pregnant and lactating rats a striking proliferation of lactotrophs occurs to meet the increased demands for prolactin. Following interruption of lactation the redundant lactotrophs undergo a massive degeneration until pre-pregnant proportions are re-established. Immunocytochemical detection of prolactin allows the recognition of degenerating lactotrophs until advanced stages of degeneration and leads to the conclusion that this process is autolytic in nature. Histochemistry of acid phosphatase reveals a remarkable accumulation of this enzyme in Golgi cisternae and lysosomes. At later stages of degeneration the acid phosphatase spreads throughout the entire cell. The presence of increased numbers of necrotic cells appears to activate phagocytosis of stellate cells and, to a lesser extent, of follicular cells. Stellate cells responsible for the secondary processing of cell residues are isolated cells characterized by a prominent oval nucleus and an electron-lucent cytoplasm with scarce organelles and extensive cytoplasmic processes. They appear as scavenger cells engulfing cell remnants and debris. Immunocytochemistry of S-100 protein discloses differential staining of two types of cell, one forming clusters of 2–4 cells with faint immunoreactivity, while the other type consists of isolated cells with a stellate profile and stronger labelling to S-100 protein.
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Burdman, J. A., Calabrese, M. T. & Macleod, R. M. (1983) Hyperprolactinemia and DNA synthesis in the pituitary gland of the rat. J. Endocrinol 97, 65–74.
Chang, N. G. & Nikitovitch-Winer, M. B. (1976) Correlation between suckling-induced changes in the ultrastructure of mammotrophs and prolactin release. Cell Tissue Res. 166, 399–406.
Cocchia, D. & Miani, N. (1980) Immunocytochemical localization of the brain-specific S-100 protein in the pituitary gland of adult rat. J. Neurocytol. 9, 771–82.
Danscher, G. (1981) A photochemical method for light and electron microscopy. Histochemistry 71, 81–8.
Dingemans, K. & Feltkamp, C. A. (1972) Nongranulated cells in the mouse adenohypophysis. Z. Zellforsch. 124, 387–405.
Farquhar, M. G. (1957) Corticotrophs of the rat adenohypophysis as revealed by electron microscopy. Anat. Rec. 127, 291.
Farquhar, M. G. (1971) Processing of secretory products by cells of the anterior pituitary gland. Mem. Soc. Endocrino. 19, 79–122.
Farquhar, M. G., Skutelsky, E. H. & Hopkins, C. R. (1975) Structure and function of the anterior pituitary and dispersed pituitary cells. In vitro studies. In The Anterior Pituitary (edited by Tixier-Vidal, A. & Farquhar, M. G.) pp. 83–135. New York: Academic Press.
Faulk, W. P. & Taylor, G. M. (1971) An immunocolloid method for the electron microscope. Immunocytochemistry 8, 1081–83.
Frens, G. (1973) Controlled nucleation of the regulation of the particle size in monodisperse gold solutions. Nature Phys. Sci. 241, 20–2.
Gale, T. F. (1972) An electron microscopic study of the pars distalis of the dog adenohypophysis. Z. Anat. Entwickl. Gesch. 137, 188–99.
Girod, G., Trouillas, J. & Dubois, M. P. (1985) Immunocytochemical localization of S100 protein in stellate cells (folliculo-stellate cells) of the anterior lobe of the normal human pituitary. Cell Tissue Res. 243, 505–11.
Goluboff, L. G. & Ezrin, C. (1969) Effect of pregnancy on the somatotroph and the prolactin cell of the human adenohypophysis. J. Clin. Endocr. Metab. 29, 1533–8.
Haggi, E. S., Torres, A. I., Maldonado, C. A. & Aoki, A. (1986) Regression of redundant lactotrophs in rat pituitary gland after cessation of lactation. J. Endocrinol. 111, 367–73.
Heap, P. F., Lederis, K. & Neumann, F. (1971) Effects of cyproterone on the ultrastructure of the rat adenohypophysis. Mem. Soc. Endocrinol. 19, 147–60.
Holgate, C. S., Jackson, P., Cowen, P. N. & Bird, C. C. (1983) Immunogold-silver staining: new method of immunostaining with enhanced sensitivity. J. Histochem. Cytochem. 31, 938–44.
Hymer, W. C., Mastro, A. & Griswold, E. (1970) DNA synthesis in the anterior pituitary of the male rat: effect of castration and photoperiod. Science 167, 1629–30.
Kagayama, M. (1965) The follicular cell in the pars distalis of the dog pituitary gland: an electron microscope study. Endocrinology 77, 1053–60.
Kunert-Radek, J. & Pawlikowski, M. H. (1975) The effect of thyrotropin releasing hormone on cell proliferation in the anterior pituitary gland of thyroidectomized rats. Neuroendocrinology 17, 92–5.
Leuenberger, P. M. & Novikoff, A. B. (1975) Studies on microperoxisomes. VII. Pigment epithelial cells and other cell types in the retina of rodents. J. Cell Biol. 65, 324–34.
Maldonado, C. A. & Aoki, A. (1986a) Influence of embedding media on prolactin labelling with immunogold techniques. Histochem. J. 18, 429–33.
Maldonado, C. A. & Aoki, A. (1986b) Improvement of prolactin immunolabelling in osmium-fixed acrylic-embedded pituitary gland. Basic Appl. Histochem. 30, 301–5.
Marin, F., Boya, J. & Lopez-Carbonell, A. (1989) Immunocytochemical localization of vimentin in stellate cells (Folliculostellate cells) of the rat, cat and rabbit pituitary pars distalis. Anal. Embyrol. 179, 491–5.
Massa, E. M. & Aoki, A. (1971) Simple method for purification of glutaraldehyde. Acta Physiol. Latinoamer. 21, 161–3.
Nakajima, T., Yamaguchi, H. & Takahashi, K. (1980) S100 protein in folliculostellate cells of the rat pituitary anterior lobe. Brain Res. 191, 523–31.
Pasteels, J. L. (1963) Recherches morphologiques et experimentales sur la secretion de prolactin. Arch. Biol. 74, 439–553.
Reifel, C. W., Stokreef, J. C. & Shin, S. H. (1989) Crystalloid inclusions in folliculostellate cells of adenohypophysis following estrogen withdrawal from primed male rats. Acta Anat. 135, 219–21.
Schechter, J., Ahmad, N. & Weiner, R. (1988) Activation of anterior pituitary folliculo-stellate cells in the formation of estrogen-induced prolactin-secreting tumors. Neuroendocrinology 48, 569–76.
Shiino, M., Williams, G. & Rennels, E. G. (1972) Ultrastructural observation of pituitary release of prolactin in the rat by suckling stimulus. Endocrinology 90, 176–87.
Smith, R. E. & Farquhar, M. G. (1966) Lysosome function in the regulation of the secretory process in cells of the anterior pituitary gland. J. Cell. Biol. 31, 319–47.
Stepien, H., Karasek, E. & Pawlikowski, M. (1981) Effect of adrenalectomy and hydrocortisone on DNA synthesis in the rat anterior pituitary gland. Biochem. Biophys. Res. Commun. 100, 1531–6.
Stokreef, J. C., Reifel, C. W. & Shin, S. H. (1986) A possible phagocytic role for folliculo-stellate cells of anterior pituitary following estrogen withdrawal from primed male rats. Cell Tissue Res. 243, 255–61.
Torres, A. I. & Aoki, A. (1987) Release of big and small molecular forms of prolactin: dependence upon dynamic state of the lactotroph. J. Endocr. 114, 213–20.
Vankelecom, H., Carmeliet, P., VanDamme, J., Billiau, A. & Denef, C. (1989) Production of interleukin-6 by folliculostellate cells of the anterior pituitary gland in a histotypic cell aggregate culture system. Neuroendocrinology 49, 102–6.
Vila-Porcile, E. (1972) Le reseau des cellules folliculostellaires et les follicules de l'adenohypophyse du rat (Pars distalis). Z. Zellforsch. 129, 328–69.
Yamashita, K. (1972) Fine structure of the mouse anterior pituitary maintained in a short-term incubation system. Z. Zellforsch. 124, 465–78.
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Orgnero De Gaisán, E.M., Maldonado, C.A. & Aoki, A. Fate of degenerating lactotrophs in rat pituitary gland after interruption of lactation: a histochemical and immunocytochemical study. Histochem J 25, 150–165 (1993). https://doi.org/10.1007/BF00157988
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DOI: https://doi.org/10.1007/BF00157988