Summary
The pars tuberalis of the hypophysis of Rana temporaria presents the general structural and the cytological characteristics of an endocrine gland. It is composed of elongated cells with long, branching processes ending on the external basement membrane of the pericapillary space. The pars tuberalis cells produce secretory granules which are accumulated in the pericapillary endings of the processes.
Corresponding to its separate localization, the pars tuberalis of Rana temporaria has a separate vascularization of which the efferent capillaries anastomose with the capillary plexus of the median eminence. The general direction of the blood flow of the pars tuberalis is towards the capillaries of the median eminence. Also, the secretory products of the pars tuberalis pass into the blood stream of the hypophysial portal system.
Several characteristics of the pars tuberalis show that its function must be different from that of the pars distalis of the hypophysis. Moreover, in contrast with the pars distalis, the activity of the pars tuberalis is not regulated by neurohumoral factors.
The results show that a role of the pars tuberalis in the regulation of the activity of the pars distalis of the hypophysis is not excluded.
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References
Bloom, W., Fawcett, D. W.: A textbook of histology, ninth. edition. Philadelphia-London: W. B. Saunders 1968.
Burlet, A., Legait, H.: Etude histophysiologique et expérimentale des lobes tubéraux de la grenouille verte Rana esculenta. C. R. Ass. Anat. 137, 286–291 (1967).
Doerr-Scott, J.: L'hypophyse du Crapaud: Bufo vulgaris Laur. Etude comparative aux microscopes optique et électronique. C. R. Acad. Sci. (Paris) 260, 969–972 (1965).
—: Etude aux microscopes optique et électronique des différents types de cellules de la pars distalis et de la pars intermedia de Triturus marmoratus Latr. Ann. Endocr. (Paris) 27, 101–119 (1966).
—: Cytologie et cytophysiologie de l'adénohypophyse des amphibiens. Ann. Biol. 7, 189–225 (1968).
Green, J. D., Van Breemen, V. L.: Electron microscopy of the pituitary and observations on neurosecretion. Amer. J. Anat. 97, 177–227 (1955).
Grimley, P. M.: Selection for electron microscopy of specific areas in large epoxy tissue sections. Stain Technol. 40, 259–263 (1965).
Halmi, N. S.: Differentiation of two types of basophils in the adenohypophysis of the rat and the mouse. Stain Technol. 27, 61–64 (1952).
Hanström, B.: Gross anatomy of the hypophysis in mammals. In: Pituitary gland, vol. I: Anterior pituitary, p. 1–57. Ed. G. W. Harris and B. T. Donovan. London: Butterworths 1966.
Knowles, F., Kumar, T. C. A.: Structural changes, related to reproduction in the hypothalamus and in the pars tuberalis of the rhesus monkey. I. Hypothalamus—II. The pars tuberalis. Phil. Trans. B 256, 357–375 (1969).
Kobayashi, T., Yamainoto, K., Inatomi, M.: Electron microscopic observation on the hypothalamo-hypophyseal system in the rat. I. The ultrafine structure of the contact region between the external layer of the infundibulum and pars tuberalis of the anterior pituitary. Endocr. jap. 10, 68–80 (1963).
Legait, H., Burlet, A.: Recherches morphologiques et expérimentales sur les lobes tubéraux des Amphibiens. C. R. Soc. Biol. (Paris) 160, 2437–2439 (1966).
Morato, M. J. X.: Les relations des vaisseaux porte-hypophysaires avec la pars tuberalis et leur rôle fonctionnel probable. C. R. Soc. Biol. (Paris) 159, 520 (1965).
Oota, Y., Kurosumi, K.: Electron microscopic studies on the pars tuberalis of the rat hypophysis. Arch. histol. jap. 27, 501–520 (1966).
Purves, H. D.: Cytology of the adenohypophysis. In: Pituitary gland, vol. I: Anterior pituitary, p. 147–232. Ed. G. W. Harris and B. T. Donovan. London: Butterworths 1966.
Reynolds, E. S.: The use of lead citrate at high pH as an electron opaque stain in electron microscopy. J. Cell Biol. 17, 208–212 (1963).
Rinne, U. K.: Ultrastructure of the median eminence of the rat. Z. Zellforsch. 74, 98–122 (1966).
Stutinsky, F., Porte, A., Stoeckel, P. E.: Sur les modifications ultrastructurales de la pars tuberalis du rat après hypophysectomie. C. R. Acad. Sci. (Paris) 259, 1765–1767 (1964).
Szentágothai, J., Mess, B., Flerko, B., Halasz, B.: Hypothalamic control of the anterior pituitary. Budapest: Akadémiai Kiado 1968.
Van Oordt, P. G. W. J.: The gonadotrophin producing and other cell types in the distal lobe of the pituitary of the common frog Rana temporaria. Gen. comp. Endocr. 1, 364–374 (1961).
—: Cell types in the pars distalis of the amphibian pituitary. In: Cytologie de l'adénohypophyse, p. 301–313. Paris: Edit. Centre Nat. Rech. Sci. 1963.
Young, B. A., Foster, C. L., Cameron, E.: Some observations on the ultrastructure of the adenohypophysis of the rabbit. J. Endocr. 31, 279–287 (1965).
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Dierickx, K., Lombaerts-Vandenberghe, M.P. & Druyts, A. The structure and vascularization of the pars tuberalis of the hypophysis of Rana temporaria . Z. Zellforsch. 114, 135–150 (1971). https://doi.org/10.1007/BF00339471
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DOI: https://doi.org/10.1007/BF00339471