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  • Life and Medical Sciences  (5)
  • Acinar cells  (2)
  • Cathepsin B  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Variations in immunocytochemical localization of cathepsin B and thyroxine in follicular cells of the rat thyroid gland and plasma TSH concentrations over 24 hours (1989)
    Springer
    Cell & tissue research 256 (1989), S. 355-360 
    Details
    ISSN: 1432-0878
    Keywords: Thyroid gland ; Cathepsin B ; Lysosomes ; Immunocytochemistry ; Diurnal rhythm ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Immunocytochemical localization of cathepsin B and thyroxine (T4) in follicular cells of the rat thyroid gland and plasma concentrations of thyroid stimulating hormone (TSH) were examined at six evenly spaced times over 24 h. By light- and electron microscopy, immunodeposits for cathepsin B were localized in cytoplasmic granules of various sizes, whereas those for T4 were detected mainly in larger granules of the cells and in the colloid lumen. The size and location of cytoplasmic granules showing immunoreactivity for cathepsin B and T4 in the cells varied over 24 h, corresponding to a change in plasma TSH concentrations. These immunopositive large granules appeared in the apical cytoplasm at 12.00 h, when the level of TSH was highest. At 20.00 h when the level of TSH was lowest, T4-positive granules almost disappeared, and cathepsin B-positive small granules were abundantly seen in the basal region. From 00.00 h to 08.00 h, these positive granules changed in the same manner as those seen from 12.00 h to 20.00 h, associated with an increase in plasma TSH levels. These results suggest that newly formed colloid droplets migrate from the apical to the basal regions. Cathepsin B may play a role not only in the degradation of thyroglobulin but in the maturation of thyroid hormones during the migration of the granules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218892
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  • 2
    Electronic Resource
    Electronic Resource
    A histochemical study of variations in the localization of 5′-nucleotidase activity in the acinar cell of the rat exocrine pancreas over the twenty-four hour period (1983)
    Springer
    Cell & tissue research 230 (1983), S. 411-420 
    Details
    ISSN: 1432-0878
    Keywords: Pancreas (rat) ; Acinar cells ; 5′-Nucleotidase ; Circadian variation ; Cytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The circadian variation of 5′-nucleotidase (AMPase) activity was studied in rat pancreatic exocrine cells. The localization of this enzyme, often associated with the plasmalemma, was studied by ultracytochemical methods at six time points over the 24-h period. The localization of AMPase activity exhibited a clear-cut circadian variation. During the light span strong activity was observed on the luminal plasmalemma, negative or weak activity on the baso-lateral plasmalemma and clearly visible activity on intracellular structures such as cytoplasmic vacuoles (fragmentation-like vesicles), dilated rims of the Golgi cisternae (or cisternal ends of the Golgi stacks), condensing vacuoles and lysosomal bodies. During the dark span the activity was detectable only on the baso-lateral plasmalemma. The fact that AMPase activity could not be found on the luminal plasmalemma during the dark span suggests that the luminal membranes may be replaced by the membranes of secretory granules, which do not display AMPase activity. The intracellular localization of AMPase activity during the light span, especially at 08.00 h, includes all cytoplasmic compartments which have hitherto been associated with the intracellular pathway for membrane retrieval from the plasmalemma. Moreover, the appearance of the activity in the dilated rims of the Golgi stack and condensing vacuoles indicates that these compartments may constitute a functional unit.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00213814
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  • 3
    Electronic Resource
    Electronic Resource
    A morphometric study of 24-hour variations in subcellular structures of the rat pancreatic acinar cell (1982)
    Springer
    Cell & tissue research 226 (1982), S. 609-620 
    Details
    ISSN: 1432-0878
    Keywords: Pancreas (rat) ; Circadian variations ; Acinar cells ; Zymogen granules ; Stereology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Subcellular structures of pancreatic acinar cells were examined at six evenly spaced time points in the 24-h period (light cycle: 06.00 h–18.00 h) in four Wistar male rats at each time point. At each sampling point, the area and circumference of acinar cell bodies and the area, number and circumference of their cytoplasmic organelles were measured using a semiautomatic computer system for morphometry and a point-counting method. The area, number and circumference-area ratio of the cytoplasmic organelles were subject to strong circadian variations, and the cellular area and circumference exhibited weak circadian variations. Variation pattern of the cytoplasmic organelles suggested an intracellular route for secretory proteins during a 24-h span. From the results it was possible to divide the 24-h period into three stages. 1. The resting or protein synthetic stage (00.00 h to 08.00h): the area of the rough surfaced endoplasmic reticulum (rER) was strongly increased, and that of zymogen granules was clearly decreased. 2. The granule accumulation stage (08.00h to 16.00h): the area of the rER was markedly decreased; that of zymogen granules was increased. 3. The secretion stage (16.00 h to 00.00): as a result of the release of zymogen granules from the acinar cell, the area of zymogen granules decreased, and that of the rER increased. The relationship between the area of the rER and zymogen granules varied in a reciprocal manner. Other cytoplasmic organelles, namely the Golgi complex, condensing vacuoles, mitochondria and lysosomes also varied prominently during the 24-h span, corresponding to variations in the rER and zymogen granules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214788
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  • 4
    Electronic Resource
    Electronic Resource
    Changes in immunoreactivity for cathepsin H in rat type II alveolar epithelial cells and its proteolytic activity in bronchoalveolar lavage fluid over 24 hours (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 230 (1991), S. 519-523 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Variations in immunoreactivity for cathepsin H in rat type II alveolar epithelial (type II) cells and in its proteolytic activity in bronchoalveolar lavage fluid (BALF) were examined at six evenly spaced times over 24 hr (light period: 0600-1800 hr). Ring-shaped immunodeposits for cathepsin H were detected in type II cells (lamellar bodies), their sizes varying over 24 hr. The large ring-shaped immunodeposits increased during the light period, decreasing rapidly from 2000 to 0000 hr. Small intense immunodeposits abundantly appeared in the cells at 0000 hr. The area densities of immunodeposits in type II cells and their optical densities also varied with the time of day; both densities were high during the dark period, peaking at the mid dark period, whereas they were decreased during the light period. Proteolytic activities of cathepsin H in BALF (6 ml/rat) examined at each time revealed a distinct variation over 24 hr, corresponding to the variation in the immunoreactivity in type II cells. The activities in BALF were high from 1600 to 0400 hr and low at 0800 hr. These results suggest that the variation in immunoreactivity for cathepsin H in type II cells over 24 hr reflects the intracellular growth of lamellar bodies and secretory activity of the cells. Similar variations in the immunoreactivity and proteolytic activity of cathepsin H in the cells and BALF indicate its cosecretion with surfactants.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092300411
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  • 5
    Electronic Resource
    Electronic Resource
    Bimodal variations in subcellular structures of rat thyroid follicular cells during 24 hours: Fine structural and morphometric studies (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 175 (1986), S. 1-13 
    Details
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: To clarify 24-hr variations in rat thyroid follicular cells under physiological conditions, their subcellular structures were examined at six evenly spaced times during 24 hr by using a morphometric technique. The volume, surface, and numerical densities of subcellular structures varied distinctly over each 24-hr period, with a bimodal pattern. The cellular and nuclear volumes varied also bimodally over 24 hr. A decrease in the surface density of the apical plasmalemma at 1200 and 0000 hr coincided with an increase in volume density of cytoplasmic granules representing colloid droplets and dense bodies. Most granules (colloid droplets) appearing at these times were reduced in electron density. At other times, especially at 1600 and 0400 hr, morphometric parameters of rough endoplasmic reticulum (rER), Golgi complex, and subapical vesicles were prominently increased, although values for rER did not peak at 1600 hr. At these times, the volume densities of cytoplasmic granules, most of which were heterogeneous and of homogeneous electron density, were decreased. These findings coincided with immediate and subsequent reactions of follicular cells after injection of thyroid-stimulating hormone (TSH). From the evidence, it seems likely that variations in follicular cells over a 24-hr period reflect variations in blood TSH concentration. The total membrane areas of membrane components in follicular cells were calculated from the morphometric measurements. These areas fluctuated unimodally during 24 hr over a 65% range. This suggests that the membranes in follicular cells are subjected to cyclic degradation and regeneration during each 24-hr period.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1001750102
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  • 6
    Electronic Resource
    Electronic Resource
    Changes in colloid droplets and dense bodies in rat thyroid follicular cells during 24 hours: Fine structural and morphometric studies (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 175 (1986), S. 15-22 
    Details
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Two changes in cytoplasmic granules, corresponding to colloid droplets and dense bodies, in rat thyroid follicular cells during 24 hr were analyzed morphometrically in the apical, intermediate, and basal parts of the cells. The volume and surface densities of the cytoplasmic granules and their volumes and surface areas in the apical and intermediate parts varied bimodally over a 24-hr day, being high at 1200 and 0000 hr and low at other times. In apical and intermediate regions, colloid droplets were predominant at 1200 and 0000 hr, whereas the cytoplasmic granules became heterogeneously or homogeneously electron-dense at other times. In the basal part, these morphometric parameters were not synchronized with those in the other two regions, showing lower values. The basal cytoplasmic granules were heterogeneously or homogeneously electron-dense. Small, homogeneously dense granules appeared in both the apical and intermediate parts and in the basal part with a certain time lag. These granules were often in contact with colloid droplets in the lumenal two parts at 1200 and 0000 hr. Their numerical densities were low in the apical part, but high in the intermediate and basal parts. These results suggest that newly formed colloid droplets migrate from the apical through the intermediate to the basal part, changing in appearance as they go. Moreover, it seems likely that small, homogeneously dense granules are a final form of cytoplasmic granule. They may be reused for degradation of colloidal protein.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1001750103
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  • 7
    Electronic Resource
    Electronic Resource
    Variations in immunoreactivity of angiotensinogen and cathepsins B and H in rat hepatocytes over 24 hours (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 187 (1990), S. 175-182 
    Details
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: To examine variations in immunoreactivity of angiotensinogen and cathepsins B and H in hepatocytes over 24 hr, rat liver was examined immunohistochemically. Immunoreactivity of angiotensinogen and cathepsins B and H in periportal and perivenous hepatocytes varied significantly over 24 hr, when analyzed by an image analyzer. In periportal and perivenous hepatocytes, immunoreactivity of angiotensinogen was highest at 0800 hr and lowest at 2000 hr or 0000 hr, whereas that of cathepsins B and H was maximal at 1600 hr and minimal at 0400 hr or 0800 hr. Proteolytic activities of cathepsins B and H in liver extracts varied in parallel to the variations in immunoreactivity of these enzymes. Localization of angiotensinogen in the liver acinus was inversely correlated to that of cathepsins B and H; angiotensinogen was predominantly localized in periportal hepatocytes, but cathepsins B and H were in perivenous hepatocytes at each time point examined. These results suggest that angiotensinogen in hepatocytes is actively synthesized and secreted early in the light period, whereas proteolytic activities in lysosomes of hepatocytes are augmented late in the light period.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1001870206
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  • 8
    Electronic Resource
    Electronic Resource
    Fluctuations in follicular structures of rat thyroid glands during 24 hours: Fine structural and morphometric studies (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 175 (1986), S. 23-33 
    Details
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The thyroid follicles of adult male Wistar rats were examined at six evenly spaced times over 24 hr with a morphometric technique. Follicular structures were subjected to distinct variations during 24 hr, with respect to volume and numerical densities of follicles in the thyroid gland, and diameters, volumes, cell numbers, and luminal surface areas of individual follicles. Variations in follicular structures were divided into two phases: a large follicular phase at 1200, 1600, and 2000 hr and a small follicular phase at the other times. Although volume densities of follicles in the gland varied with a small amplitude, diameters, volumes, and cell numbers of individual follicles exhibited distinct fluctuations during 24 hr. Numerical densities of follicles in the gland changed distinctly during the small follicular phase as well. Degenerating follicular cells appeared in the follicular lumen especially at 1600 hr. No mitotic follicular cells were found throughout the experiment. Furthermore, one to three follicular cells of two adjacent follicles were often in contact with each other at 0400, 0800, and 1200 hr, and these follicles were lined by the common basement membranes. These results suggest that the variations in follicular structures during the small follicular phase occur in the form of follicle separation and fusion. Moreover, the morphological and morphometric variations in follicles reflect those in subcellular structures of follicular cells previously reported by us.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1001750104
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