Ultrastructure of the pituitary complex in the genus Raia (elasmobranchii)

I. the pars neurointermedia
  • P. F. D. Chevins


A single secretory cell type is predominant in the neurointermediate lobes of Raia clavata, R. batis and R. radiata; a few glia cells are also present. Nerve bundles entering the lobe between the cell cords contain two secretory nerve types, and possibly a third type devoid of secretory granules. Type A axons containing granules of mean diameter 2000 Å are presumed peptidergic, and type B axons with 1000 Å granules, aminergic. Both axon types make numerous synaptoid contacts with the secretory cells, and also make contact with the basement membrane of the capillary walls. A few neuroglial contacts were also noted. The implications of this innervation pattern with respect to the control of MSH secretion are discussed. A colloid-filled cavity present in the lobes of two juvenile fish is interpreted as a remnant of Rathke's pouch. It is lined with a layer of interdigitating undifferentiated cells bearing microvilli, interspersed by a few ciliated cells.

Key words

Hypophysis Intermediate lobe Genus Raia Neurosecretory fibres Catecholamine fibres 


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  1. Acher, R., Chauvet, J., Chauvet, M. T., Crepy, D.: Phylogenie des peptides neurohypophysaires: Isolement d'une nouvelle hormone, la glumitocine (Ser4-Gln8-ocytocine) présente chez un poisson cartilagineux, la raie (Raia clavata). Biochim. biophys. Acta (Amst.) 107, 393–396 (1965).Google Scholar
  2. Bargmann, W.: Weitere Untersuchungen am neurosekretorischen Zwischenhirn-Hypophysensystem. Z. Zellforsch. 42, 247–272 (1955).Google Scholar
  3. Chevins, P. F. D.: The anatomy and physiology of the pituitary complex in the genus Raia, Elasmobranchii. Ph. D. Thesis, Leeds University 1968.Google Scholar
  4. Chevins, P. F. D., Dodd, J. M.: Colour change in the skates and the innervation of the neuro-intermediate lobe. Gen. comp. Endocr. 13, 499 (1969).Google Scholar
  5. Chevins, P. F. D., Dodd, J. M.: Pituitary innervation and control of colour change in the skates, Raia naevus, R. clavata, R. montagui and R. radiata. Gen. comp. Endocr. 15, 232–241 (1970).Google Scholar
  6. Gersch, M.: General aspects and problems in comparative endocrinology. Opening lecture to 6th Conference of European Comparative Endocrinologists, Montpellier 1971. Gen. comp. Endocr. In press.Google Scholar
  7. Gray, E. G., Guillery, R. W.: Synaptic morphology in the normal and degenerating nervous systems. Int. Rev. Cytol. 19, 111–182 (1966).Google Scholar
  8. Heller, H., Leathers, D. H. G., Lane, G. J.: The effect of neurohypophysial hormones on the oviduct of an elasmobranch fish, Scylliorhinus caniculus. J. Endocr. 50, 537–538 (1971).Google Scholar
  9. Howe, A., Maxwell, D. S.: Electron microscopy of the pars intermedia of the pituitary gland in the rat. Gen. comp. Endocr. 11, 169–185 (1968).Google Scholar
  10. Kamer, J. C. van de, Verhagen, Th. G.: A cytological study of the neurohypophysis of Scylliorhinus caniculus. Z. Zellforsch. 49, 229–246 (1955).Google Scholar
  11. Knowles, F. G. W.: Evidence for a dual control by neurosecretion of hormone release in the pituitary of the dogfish, Scylliorhinus stellaris. Phil. Trans. B 249, 435–455 (1965).Google Scholar
  12. Knowles, F. G. W., Weatherhead, B., Martin, R.: The ultrastructure of neurosecretory fibre terminals after zinc-iodine-osmium impregnation. Aspects of Neuroendocrinology p. 159–165, W. Bargmann and B. Scharrer (eds.). Berlin-Heidelberg-New York: Springer 1970.Google Scholar
  13. Mellinger, J. C. A.: Les relations neuro-vasculo-glandulaires dans l'appareil hypophysaire de la rousette Scylliorhinus caniculus L. Thèses Imprimerie Alsatia Colmar 1963aGoogle Scholar
  14. Mellinger, J. C. A.: Étude histophysiologique du système hypothalamohypophysaire de Scylliorhinus caniculus (L.) en état de mélanodispersion permanente. Gen. comp. Endocr. 3, 26–45 (1963b).Google Scholar
  15. Meurling, P.: The relations between neural and intermediate lobes in the pituitary of Squalus acanthias. Z. Zellforsch. 58, 51–69 (1962).Google Scholar
  16. Meurling, P.: Observations of nerve-types in the hypophysial stem of Raja radiata. Acta Univ. Lund. 11, 19, 1–20 (1967).Google Scholar
  17. Meurling, P., Björklund, A.: The arrangement of neurosecretory and catecholamine fibres in relation to the pituitary intermedia cells of the skate, Raja radiata. Z. Zellforsch. 108, 81–92 (1970).Google Scholar
  18. Meurling, P., Fremberg, M., Björklund, A.: Control of MSH release—in the intermediate lobe of Raja radiata (Elasmobranchii). Gen. comp. Endocr. 13, 520 (1969).Google Scholar
  19. Polenov, A. L., Belenky, M. A.: Electron microscope observations of neurosecretory elements in the neurointermediate lobe in the skates. Nature (Lond.) 208, 94–95 (1965).Google Scholar
  20. Reynolds, E. J.: The use of lead citrate at high pH as an electron opaque stain in electron microscopy. J. Cell Biol. 17, 208–212 (1963).Google Scholar
  21. Rodríguez, E. M.: Fixation of the central nervous system by perfusion of the central ventricles with a threefold aldehyde mixture. Brain Res. 15, 395–412 (1969).Google Scholar
  22. Scharrer, E.: Das Hypophysen-Zwischenhirn-System von Scyllium stellare. Z. Zellforsch. 37, 196–203 (1970).Google Scholar
  23. Vanha-Perttula, T., Arstila, A. U.: On the epithelium of the rat pituitary residual lumen. Z. Zellforsch. 108, 487–500 (1952).Google Scholar
  24. Vincent, D. S., Anand Kumar, T. C.: Electron microscopic study on the pars intermedia of the ferret. Z. Zellforsch. 99, 185–197 (1969).Google Scholar
  25. Waring, H., Landgrebe, F. W., Bruce, J. R.: Chromatic behaviour of Scyllium canicula. J. exp. Biol. 18, 306 (1942).Google Scholar

Copyright information

© Springer-Verlag 1972

Authors and Affiliations

  • P. F. D. Chevins
    • 1
  1. 1.Dove Marine LaboratoryUniversity of Newcastle upon TyneCullercoatsEngland

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