Showing papers on "Pinealocyte published in 1967"

Circadian rhythm in the serotonin content of the rat pineal gland: regulating factors.

Abstract: There is a marked circadian rhythm in the serotonin content of the rat pineal gland. The rhythm can be inverted 180° by reversal of the lighting regimen. Phase inversion is complete in 6 days. The activities of 5-hydroxytryptophan decarboxylase and monoamine oxidase in the pineal gland do not exhibit a circadian variation. The absolute increase in pineal gland serotonin produced by tryptophan or 5-hydroxytryptophan injection is much greater than in other tissues but does not vary at different times of day and night. Treatment with β-phenylisopropyhlmydrazine, a monoamine oxidase inhibitor, prevents the nocturnal decline of pineal serotonin but does not alter daytime levels. Treatment with actinomycin D partially inhibits time daytime increase in pineal serotonin.

[On axon-like endings, secretion and extrusion of the pinealocytes of the rabbit].

Abstract: Die hellen Pinealozyten des Kaninchens schicken lange, schmale, kolbenformig endigende Fortsatze in den perivaskularen Bindegewebsraum. Das Sekret der Zellen wird in typischer Weise ausgeschieden: Zahlreiche kleine Blaschen umgeben einen dichten Kern („Rosettenstruktur“). Die Ansammlung von Blaschen verschwindet, wahrend das dichte Material in den interzellularen oder perivaskularen Raum gelangt. Eine „postsynaptische Membran“ fehlt.

Influence of Pineal Body on Melanoma of Hamsters

Abstract: JORDAN1,2 described the presence of melanic granules in pineal gland of sheep and del Rio-Hortega3–5 found pigment granules in the pinealocytes of human pineal as well as in other mammals. Santamarina and Meyer Arndt6 have more recently shown that the pigment in bovine pineal was true melanin. Ultra-violet spectral curves of bovine pineal melanin showed the same characteristics as those obtained from tyrosine melanin7,8. Pineal melanin differs slightly, however, from the melanin obtained from the choroid of the ox eye. Administration of pineal extract to tadpoles9,10, to toads10 and to fishes11 produces alteration in pigmentation. Thus it is possible that pineal body not only contains melanic pigment but is also capable of inducing some form of change in pigmentation. The hamster pineal body contains pigment granules in abundance (Fig. 1). On the basis of the investigations by Santamarina and Meyer Arndt, these can be assumed to be melanic granules. No data are available at present for the effects of pineal ablation or administration of pineal extract on pigmentation of hamsters. Isolated observations in other species have suggested a possible association between pineal body and pigmentation, however, and therefore a study was undertaken to observe the effect of pineal ablation on the growth and spread of a highly pigmented and spontaneously occurring neoplasm in hamsters.

Vascular and pineal body involvement in juvenile amaurotic idiocy (Batten's disease).

Abstract: In Juvenile Amaurotic Idiocy accumulations of lipid granules are found in the vessel walls of most organs and in the pinealocytes. Morphologically and histochemically they are indistinguishable from the lipid granules found in ordinary neurons in the CNS.

Role of the nuclear membrane in smooth endoplasmic reticulum formation in white rat pinealocytes

Abstract: La glande pineale du rat blanc est etudiee ici au microscope electronique L'association observee entre les vesicules agranulaires et les «blebs» de la membrane nucleaire est un argument en faveur de la theorie selon laquelle l'origine du reticulum endoplasmique est a rechercher dans la membrane nucleaire