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  • 1990-1994  (1)
  • 1975-1979  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Two ultrastructurally distinct types of transporting tissues, the branchiostegal and the gill epithelia, in an estuarine tanaid, Sinelobus stanfordi (Crustacea, Peracarida) (1993)
    Springer
    Zoomorphology 113 (1993), S. 253-260 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary On each lateral side of the cephalothorax segments, the adult Sinelobus stanfordi has a branchial chamber which contains an elongated bag-shaped gill and is covered by a thick branchiostegite. The ultrastructural study revealed that the inner surface of the branchiostegite is composed of a transporting-type epithelium which is morphologically distinct from the gill epithelium. Both epithelia are covered by extremely thin (about 80 nm) cuticle layers, suggesting high permeability to gases, ions, and water. In contrast, the outer surface of the branchiostegite consists of ordinary epithelium covered by a very thick cuticle layer in common with the body surface. The inner branchiostegal epithelium (4–10 μm thick) has a shallow (about 1 μm deep) apical infolding system of the cell membrane (AIS) and an extensive three-dimensional tubular network (about 120 nm in diameter) which is formed by the invagination of the basolateral cell membrane (TNB). The TNB is associated with slender mitochondria and occupies the majority of the cytoplasmic area of the epithelial cell. The gill epithelium, on the other hand, is about 10 μm thick and characterized by an abundance of oval mitochondria, well-developed (4–5 μm deep) AIS, and a smooth basal cell membrane lacking any infoldings. These morphological features indicate that not only the gill epithelia, but also the inner branchiostegal epithelia, are involved in the ion-transporting processes. The ultrastructural differences between these two kinds of epithelia also suggest their different roles in the osmoregulation of this animal, since it inhabits estuaries which are subject to extreme changes in salinity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00403316
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    The structure and innervation of the sinu-atrial node of the mole heart (1976)
    Springer
    Cell & tissue research 172 (1976), S. 345-356 
    Details
    ISSN: 1432-0878
    Keywords: Mole heart ; SA node ; Innervation ; Neuromuscular relationship ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The sinu-atrial node in the heart of the mole, Mogera wogera, contains myocytes which are devoid of atrial specific granules and which may be classified into two types: electron-lucent (majority) and dark (minority). Numerous unmyelinated axon terminals, containing synaptic vesicles, face the nodal myocyte surface with interspaces of less than 300 nm. There are about 6 terminals per myocyte profile and about 10 per profile at nuclear levels. Of a total of 2717 of these terminals 85.2% are 50–200 nm from the nodal myocytes, and 9.6% form closer neuromuscular junctions, with less than 50 nm interspace and some membrane specialization. Such specializations are almost exclusively found in relation to the dark, minority-type of nodal myocyte. Myelinated nerve fibers are also numerous within the mole SA node, and may terminate almost directly on a nodal myocyte. A few nerve fibers contain many mitochondria and may represent afferent endings. Nodal capillaries are smaller and fewer than capillaries in the juxtanodal myocardium, probably indicating a lesser blood supply to the SA node than to the ordinary myocardium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00399517
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Mitochondria-rich (chloride) cells in the gill epithelia from four species of stenohaline fresh water teleosts (1977)
    Springer
    Cell & tissue research 180 (1977), S. 87-98 
    Details
    ISSN: 1432-0878
    Keywords: Chloride cell ; Stenohaline freshwater teleosts ; Gill epithelia ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The mitochondria-rich (chloride) cells have been found to be present in the gill epithelia of four species of stenohaline fresh water teleosts. The cytoplasm of these chloride cells contains an extensive network of cytoplasmic tubules which communicate with intercellular spaces bordering the lateral and basal cell surfaces. Numerous vesicles with fairly electron-dense interiors are also present in the apical cytoplasm of chloride cells. The apical surface of a chloride cell forms an apical pit, but the lumen of the pit does not appear to be in continuity with the interior of the apical vesicles and tubules inside the cell. When Carassius auratus were kept in 100, 200, 300, and 400 mOsm-diluted sea water for a month, no appreciable changes occurred in the number and fine structure of the chloride cells, except for a dilation of the apical vesicles and a slight decrease in diameter of the cytoplasmic tubules in these cells in the fishes kept in 300 and 400 mOsm. These results suggest that chloride cells may be a rather common occurrence in the gill epithelia of stenohaline fresh water teleosts, and may function in ion-transport in these fishes in fresh water environments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227031
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    Paper (German National Licenses)
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