ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-0878
    Keywords: Vascular smooth muscle ; Spontaneously hypertensive rat ; Reaggregate cultures ; Ultrastructure ; Collagen synthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Vascular smooth muscle cells were taken from the aortae of the WKY (normotensive) and SHR (spontaneously hypertensive) strains of rat by enzymatic dispersion and put into reaggregate culture. Initially the cells became individual spheroids having average diameters of 10 μm and surfaces that were either rough or smooth. The cells were far more complex than they appeared on their surfaces; after one day in culture, there was considerable internal variation in these cells. All the cells, whether WKY or SHR, lost the bulk of their cytoplasmic contents (including myofilaments, many mitochondria, and vesicular structures) in the early stages of culture and eventually became flattened. After 14 days in culture, these modified cells collected to form reaggregates that were commonly roughly spherical and several hundred μm in diameter. These reaggregates consisted of peripheral regions made up of several layers of flattened cells overlying cores formed by glia-like networks of cells similar in cytological appearance to the cells at the periphery. The meshes formed in this way contained cellular debris derived from dead cells or extrusion of cellular contents. It appears that SHR cells are quicker to form reaggregates than are WKY cells. Yet the SHR cells retained a rounded conformation after five days, whereas the WKY cells were more flattened and formed a more discrete aggregate at this stage of culture. However, by the fourteenth day of culture, differences between the two cell strains were not so pronounced, as far as could be judged by observations made with scanning and transmission electron microscopy. Both WKY and SHR cells at 14 days appeared highly secretory, possessing large Golgi systems as well as numerous ER cisternae and mitochondria. SHR cells produced greater amounts of connective tissue at all stages of culture than did WKY cells, indicating that a similar difference may contribute to the hypertension which develops naturally in situ in SHR animals.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-0878
    Keywords: Muscle ultrastructure ; (Na+, K+)-ATPase localization ; Sarcotubules ; Sarcoplasmic reticulum ; Junctional SR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary ATPase activity sensitive to ouabain was examined in both cardiac (ventricular) and skeletal (tibialis anterior) muscle cells of the mouse. Short-term fixation was combined with incubation in a medium designed to reduce artifactual deposition of lead phosphate. With incubation medium containing Na+ and K+, Pb3 (PO4)2 precipitate appears throughout the sarcoplasmic reticulum (SR) of both cardiac and skeletal cells. The precipitate generally is heavier in the junctional SR than in network SR, although the two regions are interconnected. Ouabain (1 mM) eliminates activity in the network SR of myocardial cells, but only reduces it in skeletal muscle cells. The total ATPase activity of junctional cisternae of the SR of myocardial cells does not appear to be reduced by ouabain, whereas the activity of the terminal cisternae of skeletal muscle is substantially diminished. The use of an incubation medium containing zero K+ reduces the level of activity, but not consistently. These data suggest that (Na+, K+)-ATPase is present in the network SR of both cardiac and skeletal muscle cells, and probably in the terminal cisternae of skeletal muscle cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 143 (1974), S. 409-433 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Gonadotrophic cells in the pars distalis of Anolis carolinensis often contain juxtanuclear concentrations of filaments with diameters intermediate in size (approximately 100 Å) between microtubules and microfilaments. Their size and their substructure, which gives them a tubular appearance when they are displayed in cross-section, appear to place these filaments in the “intermediate filament” category (Ishikawa et al., '68). In their juxtanuclear position in the intact animal, the intermediate filaments are collected in randomly-oriented tangles. In castrated specimens of Anolis, gonadotrophs degranulate and elongate. During this elongation, increased numbers of microtubules appear in orientation parallel to the long axis of the cell, and the 100 Å filaments reassemble in rod-like masses oriented parallel to the microtubules. This apparent distributional interaction may facilitate the elongation of the cell. Intimate physical associations between the intermediate filaments and secretory granules suggest that the filaments may act in the movement of the granules during the processes of degranulation and secretion.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 200 (1979), S. 367-382 
    ISSN: 1432-0878
    Keywords: Ruthenium red ; Skeletal muscle ; Cardiac muscle ; Membrane permeability ; Sarcoplasmic reticulum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of ruthenium red (RR) on amphibian and mammalian skeletal muscles and mammalian myocardium were examined. In skeletal muscle cells, a discrete pattern of staining can be brought about within the lumina of the terminal cisternae (junctional sarcoplasmic reticulum [SR]) by sequential exposure to RR and OsO4. After prolonged immersion in RR solution, formation of pentalaminar segments (“zippering”) occurs at various points along the longitudinal (“network”) SR tubules. Zippering can be elicited in skeletal SR at any stage of preparation prior to postfixation with OsO4. By means of dispersive X-ray analysis, both ruthenium and osmium were seen to be deposited in skeletal muscle junctional SR, and ruthenium was detected in the myoplasm as well. In skeletal muscles whose T tubules were ruptured by exposure to glycerol, the pattern of SR staining and zippering resulting from ruthenium-osmium treatment was not affected. These findings indicate that RR is capable of passage across the sarcolemma of skeletal muscle and that this passage does not occur solely under conditions in which the plasma membrane is damaged. In contrast, RR does not opacify or modify any region of the SR of cardiac muscle. However, after this treatment, randomly distributed opaque bodies, composed of parallel lamellar structures, appear throughout the myocardial cells. A few of these bodies are associated with lipid droplets, but the rest are of unknown origin. The failure of the SR of cardiac muscle to stain after exposure to ruthenium dye (even though this material enters these cells) suggests that the chemical composition of cardiac SR is significantly different from that of skeletal muscle SR.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-0878
    Keywords: Embryonic development ; Ventricular myocardium ; Transverse and axial tubules ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Developing transverse (T) tubules are found in embryonic guinea pig ventricular myocardium after approximately eight weeks of gestation. By the time of birth (nine weeks total gestation), longitudinally-oriented axial tubules connected to the T tubules also have formed, and the majority of cells closely resemble those of the adult. The form taken by the developing T and axial tubules suggests that they are generated in a manner similar to that for T tubules in chick and rat skeletal muscle, namely by repeated formation of caveolae.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 136 (1972), S. 227-245 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The stellate cell in the pars distalis of Anolis carolinensis has been studied with the electron microscope. This cell type is characterized by the lack of secretory granules, and it possesses elongate processes that insert between secretory cells. Few cytoplasmic filaments are present in these processes, and desmosomes linking them to adjacent stellate cells or to secretory cells are seen infrequently in control animals. Stellate cells are often encountered in the caudal half of the pars distalis, but they are less commonly found in the rostral half. In animals undergoing thyroidal depression, thyroidectomy cells arise in the caudal pars distalis. Concurrently, stellate cells of that region hypertrophy and exhibit increased numbers of desmosomes, complex intercellular junctions, and micropinocytotic vesicles. Injected horseradish peroxidase penetrates the intercellular spaces, enters the micropinocytotic vesicles, and is transported to the interior of the stellate cell. It is suggested that stellate cells in Anolis under certain conditions may transport materials between the bloodstream and secretory cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0741-0581
    Keywords: Vascular cell cultures ; Transmission electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: A method is described for obtaining optimal, reproducible ultrastructure of vascular smooth muscle cells and vascular endothelial cells in culture. Routinely grown cultures are prepared for TEM with a precise regimen of fixation, postfixation, en bloc staining, dehydration, and embedment. The most important aspects of this procedure are the following: (1) fixation with a percentage-gradient series of glutaraldehyde solutions at 37°C, (2) immediate postfixation with osmium tetroxide solution, and (3) block-staining with uranyl acetate solution to eliminate any extraction of constituents during subsequent processing.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...