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Control of the pars intermedia of the lizard, Anolis carolinensis

IV. Transection of the pituitary stalk. Effects on colour change and histology

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The capacity of colour change in intact lizards and in animals with a transected hypophysial stalk was studied during extended periods. It was concluded that, with certain exceptions, the skin colour of the lizards gives information on the circulating levels of MSH, and thereby on the function of the pars intermedia.

After transection of the hypophysial stalk, three phases of chromatic behaviour were recognised. During Phase I, which lasted for about 6 days (average), dark skin was retained irrespective of the colour of the background (= high MSH levels), whereas Phase II (19 days) was characterised by the inability of the animals to become brown (= low MSH levels). A gradual recovery toward normal adaptive capacity was seen during Phase III.

In the disconnected neuro-intermediate lobe, aldehyde fuchsin (AF)-positive material in the rostral region rapidly clumped and disappeared within a few days. In the caudal portion, the stainability and the varicose arrangement of fibres were retained longer, but disappeared within approximately 14 days after the operation. Proximal to the lesion, the preoptic system exhibited a marked increase in stainability with AF, starting in the median eminence and progressing in a retrograde direction toward the peptidergic nuclei.

Revascularisation of the disconnected neuro-intermediate lobe occurred during the first few days. A reinnervation of AF-fibres across the transected area into the neural lobe was observed during Phase III in most animals, but AF-fibres did not reoccupy the entire lobe. In association with an outgrowth of capillaries, the regenerating fibres formed new neural lobules. This regenerative process was accompanied by an increase in blood supply from the primary plexus of the median eminence to the neuro-intermediate lobe.

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  1. Buijs, R.M.: Intra- and extrahypothalamic vasopressin and oxytocin pathways in the rat. Pathways to the limbic system, medulla oblongata and spinal cord. Cell Tissue Res. 192, 423–435 (1978)

  2. Christ, J.F.: The early changes in the hypophysial neurosecretory fibres after coagulation. In: Neurosecretion (Proceedings of the Third International Symposium on Neurosecretion, Bristol 1961) (H. Heller and R.B. Clark, eds.) pp. 125–142. London-New York: Academic Press 1962

  3. Daniel, P.M., Prichard, M.M.L.: Distal retraction balls in the neurohypophysis after transection of the pituitary stalk. J. Comp. Neurol. 127, 321–334 (1966)

  4. Dellmann, H.-D.: Degeneration and regeneration of neurosecretory systems. Int. Rev. Cytol. 36, 215–315 (1973)

  5. Dellmann, H.-D., Owsley, P.A.: Investigations on the hypothalamo-neurohypophysial neurosecretory system of the grass frog (Rana pipiens) after transection of the proximal neurohypophysis. II. Light- and electron-microscopic findings in the disconnected distal neurohypophysis with special emphasis on the pituicytes. Z. Zellforsch. 94, 325–336 (1969a)

  6. Dellmann, H.-D., Owsley, P.A.: Autoradiographic studies on the neurosecretory hypothalamo-hypophysial system of the grass frog (Rana pipiens) after disconnection of the distal hypophysis. Experientia (Basel) 25, 197–199 (1969b)

  7. Dellmann, H.-D., Rodriguez, E.M.: Comparative study of the ultrastructure and hormonal content of the proximal and distal stumps of the transected neurosecretory hypothalamo-hypophysial system. Experientia 26, 414–415 (1970)

  8. Geldern, Ch. E. von: Color changes and structure of the skin of Anolis carolinensis. Proc. Calif. Acad. Sci. 10, 77–117 (1921)

  9. Gesell, M.S., Callard, I.P.: The hypothalamic-hypophysial neurosecretory system in the iguanid lizard, Dipsosaurus dorsalis: A qualitative and quantitative study. Gen. Comp. Endocrinol. 19, 397–404 (1972)

  10. Goldman, J.M., Hadley, Mac E.: In vitro demonstration of adrenergic receptors controlling melanophore responses of the lizard, Anolis carolinensis. J. Pharm. Exp. Therap. 166, 1–7 (1969)

  11. Hadley, Mac E., Goldman, J.M.: Physiological color changes in reptiles. Am. Zoologist 9, 489–504 (1969)

  12. Haider, S., Sathyanesan, A.G.: On some interesting features of the hypothalamo-hypophysial vascularization in the lizard Hemidactylus flaviviridis. Experientia 29, 1424–1425 (1973)

  13. Haider, S., Sathyanesan, A.G.: Hypothalamo-hypophysial neurosecretory and portal system of the Indian wall lizard, Hemidactylus falvivridis. Acta Anat. 88, 502–519 (1974)

  14. Iturriza, F.C., Restelli, M.A.: Neurosecretion in the distal stump of the sectioned hypothalamic-hypophyseal tract in the toad. Z. Zellforsch. 81, 297–302 (1967)

  15. Kleinholz, L.H.: Studies in reptilian colour changes II. The pituitary and adrenal glands in the regulation of the melanophores of Anolis carolinensis. J. Exp. Biol. 15, 474–491 (1938a)

  16. Kleinholz, L.H.: Studies in reptilian colour changes III. Control of the light phase and behaviour of isolated skin. J. Exp. Biol. 15, 492–499 (1938b)

  17. Larsson, L., Rodríguez, E.M., Meurling, P.: Control of the pars intermedia of the lizard, Anolis carolinensis. II. Ultrastructure of the intact intermediate lobe. Cell Tissue Res. 198, 411–426 (1979a)

  18. Larsson, L., Rodríguez, E.M., Meurling, P.: Control of the pars intermedia of the lizard, Anolis carolinensis. III. Changes in ultrastructure of the disconnected neuro-intermediate lobe. Cell Tissue Res. 199, 1–23 (1979b)

  19. Meurling, P., Larsson, L.: Pars intermedia control with and without innervation — studies in elasmobranchs and a lizard. In: Neurosecretion — The final neurosecretory pathway. (VI International Symposium on Neurosecretion, London 1973) (F. Knowles and L. Vollrath eds.) pp. 198–206. Berlin-Heidelberg-New York: Springer Verlag 1974

  20. Meurling, P., Willstedt, A.: Vascular connections in the pituitary of Anolis carolinensis with special reference to the pars intermedia. Acta Zool. 51, 211–218 (1970)

  21. Parker, G.H., Starratt, S.A.: The effect of heat on the color changes in the skin of Anolis carolinensis CUV. Proc. Am. Acad. Arts Sci. 40, 457–466 (1904)

  22. Rodríguez, E.M.: Fixation of the central nervous system by perfusion of the cerebral ventricles with a threefold aldehyde mixture. Brain Res. 15, 395–412 (1969)

  23. Rodríguez, E.M., Dellmann, H.-D.: Hormonal content and ultrastructure of the disconnected neural lobe of the grass frog (Rana pipiens). Gen. Comp. Endocrinol. 15, 272–288 (1970a)

  24. Rodríguez, E.M., Dellmann, H.-D.: Ultrastructure and hormonal content of the proximal stump of the transected hypothalamo-hypophysial tract of the frog (Rana pipiens). Z. Zellforsch. 104, 449–470 (1970b)

  25. Rodríguez, E.M., Larsson, L., Meurling, P.: Control of the pars intermedia of the lizard, Anolis carolinensis. I. Ultrastructure of the intact neural lobe. Cell Tissue Res. 186, 241–258 (1978)

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Correspondence to Dr. Leonard Larsson.

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Supported by grants from the Swedish Natural Science Research Council and the Royal Physiographic Society of Lund

The authors are indebted to Mrs. Ingrid Hallberg and Mrs. Kirsten Thörneby for valuable technical assistance and skillful attention to the animals and to Miss Inger Norling for photographic aid

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Larsson, L., Meurling, P. Control of the pars intermedia of the lizard, Anolis carolinensis . Cell Tissue Res. 204, 201–216 (1979).

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Key words

  • Colour change
  • Neuro-intermediate lobe
  • Hypophysis
  • Transection
  • Preoptico-neurohypophysial system
  • Histology
  • Anolis carolinensis