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STUDIES ON HYPOTHALAMIC NEUROSECRETION IN AMPHIBIANS UNDER SEVERAL EXPERIMENTAL CONDITIONS

1959; Volume: 9; Issue: 2 Linguagem: Inglês

10.2974/kmj1951.9.197

1883-6135

Noboru Shiozaki,

Lipid Membrane Structure and Behavior

Neurosecretory phenomena in the adults of Bufo vulgaris formosus and Rana nigromaculata under the normal and the experimental conditions were studied histologically.Two kinds of the neurosecretory activities in the cells of the preoptic nucleus could be demonstrated which seems to be responsible for the production of different kinds of secretory material, for these neurosecretes the terms of “A substance” and “B substance” were given by the present anthor as follows.One of the secretory activities is concerned with the production of fine granular secretes (B substance) which are stained with aniline blue component of Mallory's triple stains and chrome-alume hematoxylin (CH) in Gomori's stains, rejecting iron-hematoxylin. As the results of the histological observations, it could be mentioned that the preoptico-hypophysial tract served as a pathway for this neurosecrete into the neurohypophysis. Another kind of neurosecretory material (A substance) was in the form of large or small spherules and showed trong affinities for acid fuchsin, iron hematoxylin and CH.Production of “A substance” is pronounced remarkably in the female toads in the breeding season and become feeble in summer. When the animals were brought in the cold circumstance in summer, there were observed considerable increase of the secretes.A series of experiments in which various kinds of drugs were injected to the hypophysectomized frogs showed that the cells of the preoptic nucleus were stimulated to produce “A substance” by Anteron, Prehormon and Progynon. Under such a condition, “A substane” which was released directly into the interstitial spaces, passed over the optic chiasma and reached at the tissues of eminentia interpeduncularis where it was discharged into the blood circulations. On their way to the eminentia interpeduncularis, “A substance” loses the stainability for CH and gains for phloxine.As to the results of the experiments mentioned, some considerations were made concerning the possible physiological influences of “A substance” on the gonadotrophic activity of the adenohypophysis.