Occurrence and regional distribution of calcareous concretions in the rat pineal gland

Diehl, Bernhard J. M.

doi:10.1007/bf00236732

Cited by 21 publications

(14 citation statements)

References 26 publications

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“…Another interesting finding is that calcareous concretions were restricted to the intermediate zone, where they showed an intimate relation to the capsule, as in rats (Diehl, 1978). Lukaszyk and Reiter (1975) have suggested, and experimental evidence has been provided in Meriones unguiculatus (Reiter et al, 1976) that the incidence of concretions is directly related to the secretory activity of the pinealocytes in a given gland.…”

Section: Discussionmentioning

confidence: 91%

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Structural dissimilarities in different regions of the pineal gland of pirbright white guinea-pigs

Jung

Vollrath

1982

J. Neural Transmission

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In the present study, the proximal, intermediate and distal parts of dumbbell-shaped pineal glands of Pirbright White guinea-pigs were investigated with respect to structural dissimilarities. The most conspicuous difference was that while in the proximal part the pinealocytes were arranged in a random fashion, the intermediate and distal regions, except a small ventral area in the latter, exhibited a prominent follicular arrangement of the pinealocytes. Concretions were restricted to the subcapsular region of the intermediate part, whereas cells with hyperchromatic nuclei increased in number in an anterior-posterior direction. In males, pinealocyte nuclear size did not differ significantly in the regions investigated, whereas in females the karyometric results were much more heterogeneous. Exposure of male guinea-pigs to continuous illumination for 45 days resulted in (i) a 25% decrease of pineal volume, the intermediate area being relatively little affected, (ii) an increase in the number of follicles and (iii) a decrease in pinealocyte nuclear size, especially in a ventral zone of the proximal part of the pineal gland.

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Section: Discussionmentioning

confidence: 91%

“…According to this assumption the intermediate part should be particularly active in secretion. However, according to Diehl (1978) the occurrence of concretions may be related to a reduced drainage of intercellular fluid.…”

Section: Discussionmentioning

confidence: 94%

Structural dissimilarities in different regions of the pineal gland of pirbright white guinea-pigs

Jung

Vollrath

1982

J. Neural Transmission

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“…There are acervuli in the connective tissue of the pineal organ as well (Bargmann, 1943(Bargmann, , 1977Voss, 1957;Wildi and Frauchinger, 1965;Macpherson and Matheson, 1979;Diehl, 1978;Jung and Vollrath, 1982;Allen et al, 1982). The pineal connective tissue "capsule" mentioned by earlier authors actually consists of arachnoid and pia mater forming the pineal meninges, and is the continuation of the meninges of the diencephalon (Vigh et al, 1989a,b; see also Bargmann, 1943).…”

Section: Immunocytochemistry Of Transmitter Substancesmentioning

confidence: 98%

Immunocytochemistry and calcium cytochemistry of the mammalian pineal organ: A comparison with retina and submammalian pineal organs

Vigh-Teichmann

Vígh

1992

Microscopy Res & Technique

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Morphologically the mammalian pineal organ is a part of the diencephalon. It represents a neural tissue histologically ("pineal nervous tissue") and is dissimilar to endocrine glands. Submammalian pinealocytes resemble the photoreceptor cells of the retina, and some of their cytologic characteristics are preserved in the mammalian pinealocytes together with compounds demonstrable by cyto- and immunocytochemistry and participating in photochemical transduction. In our opinion, the main trend of today's literature on pineal functions--only considering the organ as a common endocrine gland--deviates from this structural and histochemical basis. In mammals, similar to the lower vertebrates, the pinealocytes have a sensory cilium developed to a different extent. The axonic processes of pinealocytes form ribbon-containing synapses on secondary pineal neurons, and/or neurohormonal terminals on the basal lamina of the surface of the pineal nervous tissue facing the perivascular spaces. Ribbon-containing axo-dendritic synapses were found in the rat, cat, guinea pig, ferret, and hedgehog. In the cat, we found GABA-immunoreactive interneurons, while the secondary nerve cells, whose axons enter the habenular commissure, were GABA-immunonegative. GABA-immunogold-labeled axons run between pinealocytes and form axo-dendritic synapses on intrapineal neurons. There is a similarity between the light and electron microscopic localization of Ca ions in the mammalian and submammalian pineal organs and retina of various vertebrates. Calcium pyroantimonate deposits--showing the presence of Ca ions--were found in the outer segments of the pineal and retinal photoreceptors of the frog. In the rat and human pineal organ, calcium accumulated on the plasmalemma of pinealocytes and intercellularly among pinealocytes. The formation of pineal concrements in mammals may be connected to the high need for Ca exchange of the pinealocytes for their supposed receptor and effector functions.

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“…The pineal gland of aging rats is characterized by the formation of numerous calcified concretions (brain sand, acervuli) during the aging process (Bargmann 1943;Erdinç 1977;Diehl 1978;Vollrath 1981). Their presence in pinealocytes and perivascular spaces is related to an increase in the total calcium of the pineal gland (Humbert and Pévet 1991).…”

Section: Introductionmentioning

confidence: 98%

A possible role of collagen fibrils in the process of calcification observed in the capsule of the pineal gland in aging rats

Humbert¹,

Cuisinier²,

Voegel³

et al. 1997

Cell and Tissue Research

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The relationship between collagen fibrils and calcified concretions exclusively appearing in the pineal gland of adult/aging rats has been investigated. Deposits of lanthanum, which replace calcium ions are distributed along collagen fibrils with a repeating period of about 70 nm. Calcium has been detected histochemically between collagen bundles surrounding extracellular concretions by means of the pyroantimonate method and by X-ray microanalysis. It is associated with phosphorus. The data presented here suggest that collagen fibrils are involved in the genesis and growth of extracellular concretions located in the connective tissue surrounding the pineal gland of aging rats.

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Occurrence and regional distribution of calcareous concretions in the rat pineal gland

Cited by 21 publications

References 26 publications

Structural dissimilarities in different regions of the pineal gland of pirbright white guinea-pigs

Structural dissimilarities in different regions of the pineal gland of pirbright white guinea-pigs

Immunocytochemistry and calcium cytochemistry of the mammalian pineal organ: A comparison with retina and submammalian pineal organs

A possible role of collagen fibrils in the process of calcification observed in the capsule of the pineal gland in aging rats

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