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  • 1
    Electronic Resource
    Electronic Resource
    An immunoelectron microscopic study of corticotrophs in the golden hamster (1990)
    Springer
    Anatomy and embryology 182 (1990), S. 539-545 
    Details
    ISSN: 1432-0568
    Keywords: Corticotrophs ; Pituitary gland ; Golden hamster ; Immunocytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of corticotrophs in the pituitary of golden hamsters was studied by immunocytochemistry. Corticotrophs were classified into three types according to the different size of the secretory granules. Type A and B cells were oval or polygonal in shape containing small (158±38 nm) and medium-sized (250±53 nm) secretory granules, respectively. Type C cells were usually pyramidal or irregular in shape, and contained large secretory granules (380±78 nm). The cytoplasmic organelles of type B and C cells were fairly well developed. In all types of corticotrophs, the secretory granules varied in electron density, and were either arranged in a single row along the cell membrane, or concentrated in the vascular pole of the cytoplasm. Many of the corticotrophs sent processes to encircle neighboring somatotrophs. In the female, the proportions of type A and B cells were higher then those in the male, whereas that of the type C cells was lower. All three types of corticotrophs were observed in the early postnatal stage. The population of type A cells decreased with the advancement of postnatal development, with a concomitant increase of that of the type C cells. Thus, type A cells might represent the immature type of corticotrophs which would evolve to become the type C cells. One to 2 weeks after adrenalectomy, the number of type C cells was drastically increased. This was accompanied by their prominent changes in ultrastructure as in the type B cells. The cytoplasm became hypertrophic with extensive dilated cisternae of rough endoplasmic reticulum. The large Golgi apparatus displayed profiles seemingly involved in the formation of secretory granules. The number of type A cells was moderately decreased, and they showed little morphological alteration. Since type B and C corticotrophs exhibited a remarkable response to adrenalectomy, it is concluded that they represent the active state of corticotrophs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00186460
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  • 2
    Electronic Resource
    Electronic Resource
    Unusual Ultrastructural Features in the Superficial Pineal Gland of the Yellow-Bellied Country Rat (Rattus losea Swinhoe) (1989)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of pineal research 7 (1989), S. 0 
    Details
    ISSN: 1600-079X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The ultrastructure of the superficial pineal gland of the yellow-bellied country rat (Rattus losea Swinhoe), living under natural climatic conditions at the margin of the tropical region, was stuthed with special reference to the seasonal changes. In the rainy season with average monthly rainfall of 400 mm (light phase of 13.5 h, and temperature of 28°C) the gland was characterized by the presence of frequent large vacuoles containing flocculent material (LVFs), large condensed inclusions (LCIs) in the pinealocytes, and extensive accumulations of presumptive secretion in the extracellular compartment, suggesting an enhanced secretory activity. In the dry season with average monthly rainfall of 13 mm (light phase of 11 h, and temperature of 19°C), however, the pinealocytes were characterized by the presence of numerous clear spindles, which exhibited acid phosphatase activity; at this time there were few LVFs and LCIs and rare extracellular accumulations, suggesting a declined glandular activity. We conclude that the cellular activity of the pineal gland in R. losea, living under tropical climatic conditions, is synchronized with the annual changes of rainfall, which is apparently more important than the annual changes of photoperiod and temperature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1600-079X.1989.tb00661.x
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  • 3
    Electronic Resource
    Electronic Resource
    Synaptic Junctions Between the Adrenergic Axon Varicosity and the Pinealocyte in the Rat (1984)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of pineal research 1 (1984), S. 0 
    Details
    ISSN: 1600-079X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Intercellular relationships of sympathetic nerve fibers and cells in pineal glands of Long-Evans rats and yellow-bellied country rats (Rattus losea Swinhoe) were studied with conventional electron microscopy. Typical synapses were found between adrenergic axon varicosities and pinealocytes. The synaptic cleft was 20–30 nm thick and contained granular or filamentous material of moderate electron density. Some small granulated vesicles attached to, or fused with, the presynaptic axolemma, a feature suggesting an exocytotic release of the vesicle content. The occurrence of membranous cisternae or tubules in the synaptic nerve ending may connote the phenomenon of synaptic vesicle recycling. Beneath the postsynaptic pinealocyte plasmalemma there was a dense plaque corresponding to the postsynaptic density of neurons. Possible origins and functional significance of the synapse-making nerve fibers are also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1600-079X.1984.tb00219.x
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  • 4
    Electronic Resource
    Electronic Resource
    Cytochemical studies on cytoplasmic granular elements in the hamster pineal gland (1979)
    Springer
    Histochemistry and cell biology 61 (1979), S. 177-187 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pineal gland of adult golden hamsters (Mesocricetus auratus) was studied by various cytochemical methods at the electron microscopic level: (1) the modified chromaffin reaction specific for 5-hydroxytryptamine (5-HT), (2) argentaffin reaction, (3) zinc-iodide-osmium (ZIO) mixture reaction and (4) acid phosphatase reaction. In the pinealocytes, the dense-cored vesicles (80–160 nm in diameter) show both chromaffinity and argentaffinity, while the population of dense bodies (150–400 nm in diameter) is reactive to ammoniacal silver solution and ZIO mixture but not to the modified chromaffin reaction. After incubation for demonstration of acid phosphatase activity, reaction products are localized in some, but not all, of the dense bodies, in some of the small vesicles in the Golgi region and in one or two inner Golgi saccules. In nerve fibers in the pineal gland, small granulated vesicles are also reactive to the modified chromaffin reaction and ZIO mixture. Based upon these cytochemical results the following conclusions have been reached: (1) dense cored vesicles in the pinealocytes and small granulated vesicles in the nerve fibers of the hamster pineal gland contain 5-HT, and (2) the population of dense bodies in the pinealocytes is heterogenous, some are lysosomes and the others are possibly the granules responsible for the secretion of pineal peptides.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00496530
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  • 5
    Electronic Resource
    Electronic Resource
    Transformation of centrioles in pinealocytes of adult guinea pigs (1972)
    Springer
    Journal of neurocytology 1 (1972), S. 61-67 
    Details
    ISSN: 1573-7381
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Pinealocytes from adult guinea pigs contain conventional centrioles and microtubular sheaves composed of varying numbers of doublet and/or triplet tubules of indefinite length embedded in a dense matrix, which are assumed to be formed by elongation and dissociation of the centriolar wall. The observations suggest that one end of the wall of elongated centriolar formations may remain unbroken, while the other end may split into microtubular sheaves arranged in straight or skewed arrays. Additionally, maturing pinealocytes may possess two pairs of centrioles, of which some undergo lengthening and disintegration of the wall, giving rise to microtubular sheaves, while others remain unbroken. Cross-striated structures named denticulate or striped borders are often seen apposed to the elongated centriolar formations and are possible precursors of adjacent striated fibres.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01098646
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  • 6
    Electronic Resource
    Electronic Resource
    Development of the ciliary complex and microtubules in the cells of rat subcommissural organ (1969)
    Springer
    Cell & tissue research 96 (1969), S. 186-205 
    Details
    ISSN: 1432-0878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the rat subcommissural organs from the late stages of gestation through the postnatal to the adult stages was studied with the electron microscope. Emphasis in this report is placed on the development of the cilium with its affiliated structures. With the progress of cytodifferentiation centrioles originally located in the Golgi region migrate to the cell apex, where each then serves as a basal body to form a cilium which has a 9+2 organization of substructures. Thus, each of the mature subcommissural cells is provided with two cilia of motile type. Satellites first appear on one side of the basal body at about 17 fetal days, rapidly increase in number with age, and finally surround the basal body, forming an elaborate latticework. In the perinatal period microtubules progressively increase in number in the distal cytoplasm, which concurrently elongates and forms a prominent projection in the brain ventricle. Closely associated with the microtubules are large clusters of dense granular masses with an undefined border, which bear a close resemblance to the dense masses appearing in the differentiating cells of respiratory epithelium and having been generally assumed to be the precursor substance for centriole replication. However, the mature subcommissural cells contain no centrioles other than the preexisting pair, each of which has organized a cilium. The dense masses in the subcommissural cells are presumed to be involved in the formation of the cytoplasmic microtubules instead of new centrioles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00338766
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  • 7
    Electronic Resource
    Electronic Resource
    Fine structural changes in the hamster pineal gland after blinding and superior cervical ganglionectomy (1975)
    Springer
    Cell & tissue research 158 (1975), S. 285-299 
    Details
    ISSN: 1432-0878
    Keywords: Pineal (Hamster) ; Blinding ; Sympathetic ganglia ; Endoplasmic reticulum ; Reproductive organs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pineal glands of male hamsters 8 weeks after removal of both eyes or both superior cervical ganglia and those of untreated animals were studied by electron microscopy. In the blinded hamsters the reproductive organs were remarkably involuted, whereas the pinealocytes enlarged and were characterized by a tremendous hypertrophy of the smoothsurfaced endoplasmic reticulum, in the mesh of which some dense cored vesicles were distributed. In contrast the pinealocytes of ganglionectomized hamsters atrophied and were noted by a large number of lysosomes and sparsity of the agranular reticulum, the testes being significantly larger than the controls. The findings were interpreted to be compatible with the view that the pineal capability of producing antigonadal substance is augmented by blinding and is suppressed by cervical ganglionectomy due to the impairment of normal functioning of the pineal by denervation. It is assumed that the degree of development of the smooth endoplasmic reticulum in the pinealocyte is parallel to, and reflects that of the pineal activity. Probably the membranous organelle is involved in the elaboration of the pineal antigonadal substance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223827
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  • 8
    Electronic Resource
    Electronic Resource
    A dense-cored filamentous body in Leydig cells of the golden hamster (1979)
    Springer
    Cell & tissue research 201 (1979), S. 369-376 
    Details
    ISSN: 1432-0878
    Keywords: Leydig cells ; Filaments ; Golden hamster ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A unique cytoplasmic structure has been observed in Leydig cells of the golden hamster. It consists of a laminar core made up of electron dense material surrounded by a filamentous matrix of lower density, and is tentatively called a dense-cored filamentous body (DCFB). DCFBs vary in overall size and in configuration of the centrally disposed dense lamina. They are typically located in the vicinity of the centrosome and the Golgi complex. The body has no limiting membrane, and may be in contact with virtually every type of organelle. The DCFB is well developed in active Leydig cells, whereas it is small in the quiescent stage of the secretory cell. It is likely that the DCFB is a constant organelle in the hamster Leydig cell and may be involved in the physiological function of the Leydig cell, which remains to be specified.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236997
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  • 9
    Electronic Resource
    Electronic Resource
    Electron microscopic and cytochemical studies of the mouse subcommissural organ (1973)
    Springer
    Cell & tissue research 139 (1973), S. 217-236 
    Details
    ISSN: 1432-0878
    Keywords: Subcommissural organ ; Mouse ; Mucopolysaccharides ; Acid phosphatase activities
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In mice most of the ependymal cells of the subcommissural organ (SCO cells) are densely packed with dilated cisternae of the endoplasmic reticulum (ER) containing either finely granular or flocculent materials. The well developed supra-nuclear Golgi apparatus consists of stacks of flattened saccules and small vesicles; the two or three outer Golgi saccules are moderately dilated and exhibit numerous fenestrations; occasional profiles suggesting the budding of coated vesicles and formation of membrane-bound dense bodies from the ends of the innermost Golgi saccules are seen. A few coated vesicles and membrane-bound dense bodies of various sizes and shapes are also found in the Golgi region. The contents of the dilated ER cisternae are stained with periodic acid-silver methenamine techniques. In the Golgi complex the two or three inner saccules are stained as deeply as the dense bodies, and the outer saccules are only slightly stained. The stained contents of ER cisternae are more electron opaque than those of the outer but less opaque than those of the inner Golgi saccules and the dense bodies. Acid phosphatase activities are localized in the dense bodies, some of the coated vesicles in the Golgi region, and in the one or two inner Golgi saccules. On the basis of these results the following conclusions have been reached: (1) In mouse SCO cells the finely granular and the flocculent materials in the lumen of ER cisternae contain a complex carbohydrate(s) which is secreted into the ventricle to form Reissner's fiber; (2) the secretory substance is assumed to be synthesized by the ER and stored in its cisternae, and the Golgi apparatus might play only a minor role, if any, in the elaboration of the secretory material; (3) most of the dense bodies in the mouse SCO cells are lysosomal in nature instead of being so-called dark secretory granules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306523
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  • 10
    Electronic Resource
    Electronic Resource
    The fine structure of testicular interstitial cells in the adult golden hamster with special reference to seasonal changes (1977)
    Springer
    Cell & tissue research 183 (1977), S. 385-393 
    Details
    ISSN: 1432-0878
    Keywords: Testis ; Endoplasmic reticulum ; Golden hamster ; Macrophages ; Seasonal changes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the testicular interstitium was studied in normal adult golden hamsters sacrificed in the reproductive season (spring and summer) and in the winter. The Leydig cells in the reproductively active testes contain abundant endoplasmic reticulum (ER) and numerous mitochondria. The ER occurs in the form of flattened cisternae and tubules, the former prevailing. The cisternae are extremely extensive and are partly granular and partly agranular, their ends being continuous with the tubular reticulum. Mitochondria intervening between the cisternae are closely associated with the agranular portions of the latter. Adjacent to the Golgi complex and continuous with the centrosome a unique filamentous body with a dense laminar core is often observed. In the regressive testes, the Leydig cells show a great reduction of cytoplasmic volume and a remarkable decline of the organelles, especially agranular tubules. The possible functional significance of the tubular and cisternal ER with the associated mitochondria is discussed in relation to the biosynthesis of androgens. Macrophages appear to constitute another important population of the interstitial cell clusters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220645
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