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  • 1
    Electronic Resource
    Electronic Resource
    Fine structure of endothelial cells of vertebrates. Distribution of dense granules (1970)
    Springer
    Anatomy and embryology 131 (1970), S. 148-155 
    Details
    ISSN: 1432-0568
    Keywords: Blood vessels ; Endothelium ; Dense granules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of the vascular endothelial cells was studied, with special reference to their dense granules, in seventeen species belonging to the five classes of vertebrates. The granules were spheric or ovoid, of high electronic density, and surrounded by a single three layered membrane. In the higher vertebrates the granules are less numerous and smaller (0.1–0.4 μ) than in the lower vertebrates (0.3–0.5 μ). Tubular structures were observed in the mammalian granules, while the granular content was homogenously dense in lower vertebrates. The only bird presenting endothelial granules showed that such bodies have a structure similar to that of the mammalian studied. Two questions arise 1) is the physiological function of these granules similar in different species; and 2) are the differences observed between the granules of lower and higher vertebrates representation for the evolutionary pattern of a subcellular body.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00523293
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    The effect of monoamine synthesis-inhibitors on the ovarian compensatory hypertrophy (1969)
    Springer
    Cellular and molecular life sciences 25 (1969), S. 855-857 
    Details
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Resumen La administración continuada deα-metilpara-tirosina, un inhibidor de la síntesis de catecolaminas, impide la hipertrofia compensadora del ovario en ratas. Este efecto es prevenido por la simultânea injección de DOPA, un. precursor de las catecolaminas. El grado de la hipertrofia compensadora del ovario no fue modificado por lap-cloro-fenilalanina, un inhibidor de la síntesis de serotonina. El estudio histológico de los ovarios de los animales tratados con MPT sugiere que ésta bloquea la ovulación, no modificando aparentemente la secreción tonica de las gonadotrofinas FSH y LH.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01897919
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  • 3
    Electronic Resource
    Electronic Resource
    The surface of the choroid plexus cell under normal and experimental conditions (1968)
    Springer
    Cell & tissue research 92 (1968), S. 43-51 
    Details
    ISSN: 1432-0878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The present report is a comparative analysis of the choroid plexus cell surface under normal and experimental conditions which stimulate secretion of cerebrospinal fluid (CSF). The choroid cell surface, under normal conditions, contains cilia, ridges, and microvilli, the complexity of which varies widely from cell to cell. The intercellular clefts are rather constantly 200–400 Å across. After stimulation of CSF secretion, significant changes were observed. Pilocarpine injection leads to regularity in size and shape of the microvilli. CSF extraction and ATP injection, on the other hand, produce an expansion of the free surface which results in a complex labyrinth of ridges and swollen microvilli. Under all of these experimental conditions the intercellular gap is considerably widened. The probable significance of these findings, in relation to CSF secretion, is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00339401
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  • 4
    Electronic Resource
    Electronic Resource
    Effects of pimozide on the ultrastructure of the pars distalis in the rat (1979)
    Springer
    Cell & tissue research 199 (1979), S. 483-492 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary gland ; Rat ; Luteotroph cells ; Pimozide ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of pimozide, a dopamine receptor-blocking agent, were studied in the pars distalis of the rat. The animals received 100μg/100 g pimozide daily for 5, 10, 15, and 20 days. Pimozide induces striking ultrastructural changes after 5 days of treatment. The number of luteotroph (LTH) cells is significantly increased; they display characteristics of stimulation. The extrusion of granules into the intercellular space via exocytosis is frequently observed. The intercellular spaces are highly dilated, forming a lacunar system filled with an amorphous material, erythrocytes and involuted LTH cells. Transitional stages in the process of involution are observed in LTH cells. Luteotroph cells also form a syncytium. Twenty days after treatment the abovedescribed changes decrease in magnitude. The present findings suggest that pimozide stimulates the mechanism of synthesis and release in the luteotroph cells, an effect that is less evident with longer treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236084
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  • 5
    Electronic Resource
    Electronic Resource
    Effects of pimozide on the ultrastructure of the pars intermedia in the rat (1981)
    Springer
    Cell & tissue research 217 (1981), S. 397-403 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary gland ; Rat ; MSH-cells ; Pimozide ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of pimozide, a dopamine receptor-blocking agent, were studied in the pars intermedia of the rat. The animals received 100 μg/100 g pimozide daily for 2, 5, 10, 15, and 20 days. Pimozide induces ultrastructural changes after 5 days of treatment. About 50% of the MSH-cells display characteristics of stimulation. Their cytoplasm is partially or totally depleted of secretory granules. The rough endoplasmic reticulum displays a network of interconnecting cisternae and ribbon-like structures. The well-developed Golgi complexes exhibit numerous dilatations of their cisternae, which contain electron-dense material. The nerve endings are not altered. Twenty days after treatment, the above-described changes have not decreased in magnitude. The present findings suggest that pimozide stimulates the mechanism of synthesis and release in some MSH-cells, most probably the elements underlying an inhibitory dopaminergic control.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233589
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  • 6
    Electronic Resource
    Electronic Resource
    Testosterone-induced alterations in the reactivity pattern of the neurons in the arcuate nucleus of male mice (1983)
    Springer
    Cell & tissue research 229 (1983), S. 183-189 
    Details
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Arcuate nucleus ; Testosterone ; Karyometry ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of testosterone administration on the hypothalamic arcuate nucleus were studied in adult male mice by means of karyometry. Four animals per group were sacrificed 1, 2, and 3 h after intramuscular injection of 100 μg testosterone propionate/100 g body weight. The nuclear diameter of neurons was measured in serial coronal sections. Testosterone induced an increase in the nuclear diameter of neurons located in the dorsal and medial periventricular zones of the arcuate nucleus. The neurons exhibiting the greatest changes in nuclear diameter were situated in the rostral portion of the nuclear area examined. In the central portion of the arcuate nucleus no response to testosterone was found. The present data support previous observations showing mosaically arranged nerve-cell groups in this hypothalamic nucleus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217890
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  • 7
    Electronic Resource
    Electronic Resource
    Acetylcholine and cholinesterases (assays and light- and electron microscopical histochemistry) in different parts of the pituitary of rat, rabbit and domestic pig (1973)
    Springer
    Cell & tissue research 136 (1973), S. 1-18 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary ; Mammals ; Cholinesterases ; Acetylcholine ; Assays, light- and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Acetylcholine was measured by bioassay and cholinesterases by colorimetric assay and by light and electron microscopical histochemistry in the pars nervosa, pars intermedia and pars distalis of the rat, rabbit and domestic pig pituitaries. The highest ACh concentration was found in the rat pituitary. More butyrylcholinesterases and less acetylcholinesterase was found in the rat pituitary than in the rabbit and pig pituitaries. Light microscopical histochemistry showed greater depositions of reaction products in the rat pituitary than in the other two species. This was predominantly due to butyrylcholinesterases in the pars nervosa-pars intermedia junctional region of the rat pituitary. Electron microscopical histochemistry was of limited value for quantitative estimates of distribution and localization of cholinesterases. However, the ultrastructural localization showed that most of the reaction product in the pars nervosa was associated with pituicytes with little or no reaction product in the neurosecretory terminals or in other nerve terminals. In the pars intermedia, the reaction products were primarily on the membranes of the nuclei and endoplasmic reticulum, and in some nerve terminals. No conclusions concerning the role of acetylcholine and cholinesterase in the release of the neurosecretory hormones could be made on the basis of these findings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307676
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  • 8
    Electronic Resource
    Electronic Resource
    Elementary granules, small vesicles and exocytosis in the rat neurohypophysis after acute haemorrhage (1972)
    Springer
    Cell & tissue research 125 (1972), S. 277-288 
    Details
    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Rat ; Exocytosis ; Freeze-etching ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neural lobes of rats subjected to severe acute haemorrhage under sodium pentobarbitone anaesthesia were examined electron microscopically and the ultrastructure compared with that in anaesthetised and unanaesthetised controls. Changes in the localisation and numerical distribution of elementary granules and small vesicles in the neurohypophysial nerve endings of bled rats were consistent with the occurrence of exocytosis. The occurrence of “exocytotic profiles” was observed more frequently in freeze-etched tissue samples as compared with the material fixed for conventional electron microscopy. The ratio of small vesicles: elementary granules was shown to be significantly increased (P〈0.005) in the nerve endings of neural lobes from bled rats. Equally, the numbers of exocytotic profiles related to 1000 μm2 of neurohypophysial tissue area were significantly greater (P〈0.005) in bled rats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306626
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    Paper (German National Licenses)
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  • 9
    Electronic Resource
    Electronic Resource
    Exocytosis of cortical granules from activated oocytes of the toad, Bufo arenarum (1984)
    Springer
    Cell & tissue research 237 (1984), S. 191-194 
    Details
    ISSN: 1432-0878
    Keywords: Cellular inclusions ; Cortical granules ; Exocytosis ; Oocytes ; Amphibians (Bufo arenarum)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Observation of the cortical region of oocytes of Bufo arenarum by transmission electron microscopy reveals modifications on their surface and in the contents of the cortical granules (CG) during activation. In non-activated oocytes only amorphous cortical granules (ACG) can be observed. Activated oocytes display ACG, intermediate cortical granules containing both amorphous and membranous material (ICG), and a third type containing only membranous material (MCG). During exocytosis, CG release their contents into the perivitelline space, where the amorphous and membranous materials are found. The three types of CG found during oocyte activation suggest transformation of ACG to MCG and indicate that the different components of the cortical granules, when released into the perivitelline space, might play different roles in prevention of polyspermy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229217
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