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  • 1
    Electronic Resource
    Electronic Resource
    Functional differences between two structurally distinct types of steroidogenic cell in the avian adrenal gland (1985)
    Springer
    Cell & tissue research 240 (1985), S. 561-567 
    Details
    ISSN: 1432-0878
    Keywords: ACTH ; Adrenal zonation ; Birds ; Corticosterone ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary There are two regions of steroidogenic cells in the duck adrenal gland. An outer, subcapsular zone (SCZ), consisting of cells with irregularly shaped nuclei, shows relatively little smooth endoplasmic reticulum and mitochondria with shelf-like cristae. This region surrounds the inner zone (IZ) of the gland which is comprised of smaller cells with rounded nuclei, a more abundant smooth endoplasmic reticulum and mitochondria with tubular cristae. When samples of tissue from these distinct regions of the gland are superfused in vitro with media containing concentrations of 1–24 ACTH ranging from 100 to 1000 ng per ml (0.034 to 0.34 μM) the steroidogenic cells in both zones release corticosterone in a dose-dependent manner. The dose-responsiveness of both the SCZ and the IZ cells over this range is a complex quadratic function of the 1–24 ACTH concentration in the medium and the semilogarithmic linear portions of the dose-response curves are restricted to a narrow midrange of ACTH concentrations. Throughout the dose-response range, however, the steroidogenic cells of the IZ are more responsive to corticotropic stimulation than are the cells of the SCZ. The cells of the two zones are further distinguished by their responses to a challenge for a second time with medium containing 1–24 ACTH; the responses of the IZ cells to a second challenge were greater than those of the SCZ cells, and at a high concentration of ACTH the SCZ slices showed no significant second response.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00216345
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  • 2
    Electronic Resource
    Electronic Resource
    Functional significance of interrenal cell zonation in the adrenal gland of the duck (Anas platyrhynchos) (1979)
    Springer
    Cell & tissue research 201 (1979), S. 23-36 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal zonation ; Corticosterone ; Aldosterone ; Birds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Slices of whole adrenal gland tissue, incubated in vitro in the presence of ACTH for 1 h and 2 h produced corticosterone and aldosterone in constant ratio (16∶1). Tangential slices taken from the region immediately below the connective tissue capsule and slices taken from deeper regions of the gland consisted primarily of cells conforming to the distinct structural characteristics of the subcapsular zone (SCZ) and inner zone (IZ) tissues respectively. When samples were incubated in the presence of ACTH for 1 h and 2 h, the interrenal cells of the SCZ produced relatively more aldosterone than cells taken from the IZ of the gland. The corticosterone: aldosterone ratio for the IZ after 1 h (68∶1) and after 2 h (102∶1) were ten times greater than the ratios for the SCZ after 1 h (7∶1) and after 2 h (10∶1). The SCZ slices were not more than 60 cells thick and consisted of cells arranged in cords. These cells contained irregular nuclei, mitochondria with shelf-like cristae and a moderate abundance of smooth endoplasmic reticulum. In contrast, the production of large amounts of corticosterone by the cells of the IZ was associated with tissue containing more vascular space than the SCZ and the cells contained large round nuclei surrounded by an abundance of smooth endoplasmic reticulum and the mitochondria had tubular rather than shelf-like cristae.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238044
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  • 3
    Electronic Resource
    Electronic Resource
    The effects of colchicine, vinblastine and cytochalasins on the corticotropic responsiveness and ultrastructure of inner zone adrenocortical tissue in the Pekin duck (1984)
    Springer
    Cell & tissue research 236 (1984), S. 333-338 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal zonation ; Birds ; Corticosterone ; Cytochalasin ; Colchicine ; Vinblastine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Tissue slices superfused with medium containing no ACTH released only traces of corticosterone. Addition of ACTH to the medium caused the rate of corticosterone release to increase to a maximum about 45 min after the addition of ACTH, after which time it either remained constant or started to wane slightly. The rate of release was affected by tissue thickness; the maximum rate of corticosterone release occurred when the tissue slices were 200 μm. Stimulated adrenocortical cells had large spherical nuclei, numerous mitochondria with tubular cristae, numerous lipid droplets, and a large amount of smooth endoplasmic reticulum. Many cells had an extensive network of microfilaments adjacent to the plasma membrane and some microtubules. Prolonged superfusion caused degenerative changes in some of the cells. Both cytochalasin B and cytochalasin D, dissolved in DMSO before addition to the superfusion medium, inhibited the corticotropic responsiveness in a dose-dependent manner. Control tissue samples superfused with medium containing DMSO, but no ACTH and no cytochalasin, released significantly more corticosterone than corresponding unstimulated samples. Few or no microfilaments were observed in adrenocortical cells after treatment with cytochalasin. Neither colchicine nor vinblastine had any discernible effect on the corticotropic responsiveness. After treatment with colchicine, adrenocortical cells had an ultrastructure characteristic of inner zone stimulated cells except that they were mainly devoid of microtubules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214235
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  • 4
    Electronic Resource
    Electronic Resource
    The fine structure of the interrenal cells of the duck (Anas platyrhynchos) with evidence for the possible exocytotic release of steroids (1977)
    Springer
    Cell & tissue research 183 (1977), S. 203-220 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal glands ; Birds ; Corticosterone ; Secretions ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The duck interrenal cell possesses ultrastructural characteristics common to other steroid-secreting cells. Lipid droplets and mitochondria are abundant and lie principally at the apical end of the cell. Lipid droplets are not membrane-limited. Cisternae of smooth endoplasmic reticulum that are occasionally continuous with the less abundant rough endoplasmic reticulum are a prominent feature of the interrenal cell. Tubular profiles of rough endoplasmic reticulum often lie tangentially to mitochondria and ribosomes are either free, grouped in polyribosomal clusters, or bound to the endoplasmic reticulum. Mitochondria possess tubular cristae in the inner regions of the gland and frequently contain a paracrystalline array of small 10nm (o.d.) tubules and less frequently a hexagonal array of 40nm trilaminar rings. Other cytoplasmic components include dense bodies, residual bodies, microtubules, microfilaments and specialized single membrane-bound vesicles. Gap junctions, intermediate junctions and interdigitating processes constitute the main intercellular associations. No tight junctions were identified. The single membrane-bound vesicles which are occasionally filled with a low electron-dense, lipid-like material form septate-like “junctions” with the plasma membrane. The septa bridge an intracellular gap of 15–17 nm. The vesicles are usually located near the subendothelial space at the basal and basilateral regions of the cell. Occasionally, vesicles fuse with the plasma membrane. It is suggested that these vesicles represent morphological evidence for the exocytotic release of steroid hormones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00226620
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  • 5
    Electronic Resource
    Electronic Resource
    Evidence for the zonation of interrenal tissue in the adrenal gland of the duck (Anas platyrhynchos) (1978)
    Springer
    Cell & tissue research 192 (1978), S. 363-379 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal glands ; Birds ; Ultrastructure ; Corticosterone ; Zonation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Although interrenal tissue from the intact duck does not show a clear zonation when examined by light microscopy, the tissue does develop a well defined zonation following exposure to high and low levels of corticotropic stimulation. Under these conditions clear ultrastructural differences are seen between cells of the subcapsular zone (SCZ) and the inner zone (IZ). Based on these observations, the ultrastructure of tissue from intact birds was examined retrospectively and in addition, cell sizes and the relative volumes and areas of intracellular components were measured morphometrically. These analyses reveal morphological and quantitative differences between cells from the IZ and the SCZ. Cells of the IZ have small rounded nuclei, extensive smooth endoplasmic reticulum (SER) and mitochondria with tubular cristae, whereas cells from the SCZ contain pleomorphic nuclei, less SER and mitochondria with shelf-like cristae. The mean cell volume in the IZ is significantly less than that in the SCZ. In the SCZ cells the volume densities (volume per unit volume cytoplasm) of mitochondria and lipid droplets and the surface densities (area per unit volume cytoplasm) of the outer mitochondrial membranes are significantly greater than those in IZ cells. Conversely, in the cells of the IZ the volume densities of the nuclei and dense bodies and the surface density of the SER are greater than the corresponding values estimated for the cells of the SCZ. Although the mitochondria comprise a smaller fraction of the mean volume of IZ cells than SCZ cells, the total surface area of the cristae is approximately the same in the cells of both zones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00212319
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