ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Life and Medical Sciences  (1)
  • Tachykinins  (1)
  • 1995-1999  (2)
  • 1960-1964
  • 1
    Electronic Resource
    Electronic Resource
    In ascaris sperm pseudopods, msp fibers move proximally at a constant rate regardless of the forward rate of cellular translocation (1995)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 31 (1995), S. 241-253 
    Details
    ISSN: 0886-1544
    Keywords: Ascaris sperm ; motility ; computer-assisted motion analysis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Computer-assisted methods have been employed to obtain a high resolution description of pseudopod expansion, cellular translocation, and the subcellular dynamics of MSP fiber complexes in the motile sperm of the nematode Ascaris suum. Although Ascaris sperm translocating in a straight line or along a curved path do not retract their pseudopod or significantly alter pseudopod shape, they move in a cyclic fashion, with an average period between velocity peaks of 0.35 × 0.05 min, which is independent of the forward velocity of sperm translocation. Expansion is confined to a central zone at the distal edge of the pseudopod for sperm translocating in a straight line and to a left-handed or right-handed lateral zone in the direction of turning, for sperm translocating along a curved path. For cells translocating in a straight line, the branch points and kinks of MSP fiber complexes move in a retrograde direction in relation to the substratum at an average velocity of 11 μm per min which is independent of the forward velocity of sperm translocation. The distal (anterior) end of a fiber complex, however, moves distally at the speed of sperm translocation when it emanates from the expansion zone, but when it is displaced to a nonexpanding surface of the pseudopod, it stops moving distally. When a cell is anchored to the substratum and is, therefore, nonmotile, the velocity of fiber complexes moving in a retrograde direction doubles. The unique aspects of pseudopod and MSP fiber complex dynamics in Ascaris are compared to the dynamics of pseudopod formation and actin filament dynamics in traditional actin-based amoeboid cells, and the treadmill model for MSP polymerization is reassessed in light of the discovery that fiber complex branch points move proximally (posteriorly) at a fixed rate.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970310307
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Movement of villi induces endocytosis of NK1 receptors in myenteric neurons from guinea-pig ileum (1998)
    Springer
    Cell & tissue research 292 (1998), S. 37-45 
    Details
    ISSN: 1432-0878
    Keywords: Key words Enteric nervous system ; Enteric reflexes ; Intestine ; Tachykinins ; Substance P ; Neurotransmitters ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Agitation of villi evokes reflexes that affect the motility of the guinea-pig small intestine. NK1 receptor endocytosis was used to investigate the possible involvement of tachykinins acting on neuronal NK1 receptors in these reflexes. Segments of guinea-pig ileum were incubated at 37°C in Krebs physiological saline containing 3×10–6 M nicardipine, with or without agitation of the villi by gas bubbles. Gut segments were fixed after 0–75 min and processed for immunohistochemistry to reveal the NK1 receptors, following which cells were imaged by confocal microscopy. Initially, receptors were located on the surface and in the cytoplasm of myenteric neurons. In gut incubated without movement of the villi, NK1 receptors returned to the cell surface. After 45 and 60 min, NK1 receptors were detected almost exclusively at the cell surface of 83% and 97% (respectively) of nerve cells that were immunoreactive for NK1 receptors and only 12%–13% of the NK1 receptor fluorescence was located in the cytoplasm. Following the return of receptor to the cell surface, agitation of the villi caused a new wave of endocytosis of the NK1 receptors in 70%–80% of the NK1 receptor-immunoreactive neurons. The percentage of the NK1 receptor fluorescence that was in the cytoplasm increased more than 2-fold to 27±2% after 15 min villous agitation. Action potential blockade by tetrodotoxin (3×10–7 M) prevented the internalisation of the NK1 receptor in response to villous agitation. The degree of internalisation caused by bubbling was similar to that caused by 2×10–9 M substance P. These results indicate that, when enteric reflex circuits are activated by villous movement, tachykinins are released and cause endocytosis of the NK1 receptor in a subpopulation of myenteric neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051032
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...