Summary
An electron microscopic analysis was performed on biopsies of the infundibulum from humans undergoing hypophysectomy. Two types of nerve fibers can be distinguished by their dense core vesicles, both of which terminate in the perivascular space of small vessels within the infundibulum. Type A fibers contain dense core vesicles measuring 1,500–3,000 Å in diameter; type B fibers contain dense core vesicles measuring 500–1,000 Å in diameter. Smaller clear vesicles (200–500 Å) are found within the nerve endings in an inverse proportion to dense core vesicles. Herring bodies contain either type A or type B dense core vesicles, but frequently are filled with non-neurosecretory elements (mitochondria, dense bodies) which can also be found in nerve endings. These observations support other evidence that two types of neural control are involved in anterior pituitary regulation, but a more precise correlation between structure and function is not possible. The vascular bed of the neural infundibulum is characterized by blood vessels whose structure ranks them with venules. Short amuscular capillary segments show a cuff formed by pituicytes reminiscent of that formed by astrocytes around cerebral capillaries.
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References
Bargmann, W.: Neurosecretion. Int. Rev. Cytol. 19, 183–200 (1966).
Barry, J., et G. Cotte: Etude préliminaire, au microscope électronique de l'éminence médiane du cobaye. Z. Zellforsch. 53, 714–724 (1961).
Bergland, R. M., and R. M. Torack: Microtubules and neurofilaments in the human pituitary stalk. Exp. Cell Res. 54, 132–134 (1968).
Bradbury, S., and G. W. Harris: Neurovascular relationships in the median eminence of the rabbit. Proc. II European Reg. Conf. on Electron Microscopy, p. 477–478. Czech. Academy of Sci. Publ. House 1965.
Dean, C. R., and D. B. Hope: The isolation of purified neurosecretory granules from the bovine posterior pituitary lobes. Biochem. J. 104, 1082–1088 (1967).
Duffy, P. E., and M. Menefee: Electron microscopic observations of neurosecretory granules, nerve and glial fibers, and blood vessels in the median eminence of the rabbit. Amer. J. Anat. 117, 251–286 (1965).
Fawcett, D. W.: Comparative observations in the fine structure of blood capillaries. Int. Acad. Path. Monograph, vol. 4, p. 17–44. In: The peripheral blood vessels (ed.: J. L. Orbison). Philadelphia: Williams & Wilkins 1963.
Fuxe, K.: Cellular localization of monoamines in the median eminence and the infundibular stem of some mammals. Z. Zellforsch. 61, 710–724 (1964).
—, and T. Hökfelt: The influence of catecholamine neurons on the hormone secretion from anterior and posterior pituitary, p. 165–177. In: Neurosecretion (ed.: F. Stutinsky). Berlin-Heidelberg-New York: Springer 1967.
Grollman, A.: Clinical endocrinology and its physiological basis. Philadelphia: Pitman 1964.
Harris, G. W.: Neural control of the pituitary gland. London: Arnold 1955.
Herring, P. T.: The histological appearances of the mammalian pituitary body. Quart. J. exp. Physiol. 1, 121–159 (1908).
Holmes, R. L., and T. A. Kiernan: The fine structure of the infundibular process of the hedgehog. Z. Zellforsch. 61, 894–912 (1964).
—, and F. Knowles: Synaptic vesicles in the neurohypophysis. Nature (Lond.) 185, 710 (1960).
Knowles, F.: Neuroendocrine correlations at the level of ultrastructure. Arch. Anat. micr. 54, 343–358 (1965).
—: Neuronal properties of neurosecretory cells, p. 8–19. In: Neurosecretion (ed. F. StuTinsky). Berlin-Heidelberg-New York: Springer 1967.
Kobayashi, H., Y. Oota, H. Vemera, and T. Hirano: Electron microscopic and pharmacological studies on the rat median eminence. Z. Zellforsch. 71, 387–404 (1966).
Lederis, K.: An electron microscopical study of the human neurohypophysis. Z. Zellforsch. 65, 847–868 (1965).
McCann, S. M., and A. P. S. Dhariwal: Hypothalamic releasing factors and the neurovascular link between the brain and the anterior pituitary (vol. 1, p. 261–289). In: Neuroendocrinology (eds.: L. Martini, and W. F. Ganong). New York: Academic Press 1966.
Meurling, P.: Observations of nerve types in the hypophyseal stem of raja radiata. Acta Univ. Lund., Sect. II 19, 1–20 (1967).
Monroe, B. G.: A comparative study of the ultrastructure of the median eminence, infundibular stem, and neural lobe of the hypophysis of the rat. Z. Zellforsch. 76, 405–432 (1966).
—, and E. D. Scott: Ultrastructural changes in the neural lobe of the hypophysis of the rat during lactation and suckling. J. Ultrastruct. Res. 14, 497–517 (1966).
Oota, Y., and H. Kobayashi: The fine structure of the median eminence and the pars nervosa of the bullfrog. Z. Zellforsch. 60, 667–687 (1963).
Oppenheimer, J. H.: Abnormalities of neuroendocrine function in man (vol. II, p. 665–700). In: Neuroendocrinology (eds.: L. Martini, and W. F. Ganong). New York: Academic Press 1966.
Palay, S. L.: An electron microscope study of the neurohypophysis in the normal, hydrated, and dehydrated rat. Anat. Rec. 121, 348 (1955).
Pellegrini, I. A., and E. De Robertis: Ultrastructure and function of catecholamine containing systems, p. 355–363. In: Proc. II Int. Congr. Endocrin. Amsterdam: Excerpta Medica Foundation 1965.
Richardson, K. C.: Electron microscopic identification of autonomic nerve endings. Nature (Lond.) 210, 756 (1966).
Rinne, U. K.: Neurosecretory material passing into the hypophyseal portal system in the human infundibulum and its foetal development. Acta neuroveg. (Wien) 25, 310–324 (1963).
Sloper, J. L.: The experimental and cytopathological investigation of neurosecretion in the hypothalamus and pituitary, vol. III, p. 131–239. In: The pituitary gland (eds.: G. W. Harris and B. T. Donovan). London: Butterworths 1966.
Taxi, J., et B. Droz: Localization d'amines biogènes dans le système neurovégétatif périphérique, p. 191–202. In: Neurosecretion. (ed.: F. Stutinsky). Berlin-Heidelberg-New York: Springer 1967.
Tranzer, J. P., and H. Thoenen: Significance of empty vesicles in post-ganglionic sympathetic nerve terminals. Experientia (Basel) 23, 123–126 (1967).
Worthington, W. C., Jr.: Vascular responses in the pituitary stalk. Endocrinology 66, 19–31 (1960).
Xuereb, G. P., M. M. L. Prichard, and P. M. Daniel: The hypophyseal portal system of vessels in man. Quart. J. exp. Physiol. 39, 219–230 (1954).
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This work was supported by the National Institutes of Neurological Diseases and Blindness (NB-04161-06 and FII NB-1684-02) — The authors thank Dr. Bronson Ray for his help in obtaining these biopsies.
Markle Scholar in Academic Medicine.
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Bergland, R.M., Torack, R.M. An electron microscopic study of the human infundibulum. Z. Zellforsch. 99, 1–12 (1969). https://doi.org/10.1007/BF00338793
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DOI: https://doi.org/10.1007/BF00338793