Browsing by Author "Frank, Werner"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    Fibroblastoid and ephitelioid cells in tissue culture: differences in sensivity to ouabain and on phospholipid composition
    (1974) Hülser, Dieter F.; Ristow, Hans J.; Webb, Dennis J.; Pachowsky, Heinz; Frank, Werner
    Investigations on nine different mammalian cell lines revealed that permanently growing cells of one morphological class have numerous membrane properties in common which are different or even lacking in the other cell class. With electrophysiological methods it is shown that the sensitivity of the Na+-K+ pump to ouabain is three orders of magnitude higher in the ionically non-coupled epithelioid cells than in the ionically coupled fibroblastoid cells which respond like primary cultures. This is accompanied by considerably higher binding constants for ouabain of the epithelioid cells as was shown by [3 H] ouabain binding and membrane potential measurements. The epithelioid cells also revealed a 50% lower relative amount of phosphatidylethanolamine and a 60-fold less net synthesis of phospatidylinositol. Finally, although primary cultures cannot proliferate without serum, permanent fibroblastoid cells have a reduced serum requirement and permanent epithelioid cells can proliferate without any serum.
  • Thumbnail Image
    ItemOpen Access
    Stimulierung von Kulturen embryonaler Rattenzellen durch eine Proteinfraktion aus fötalem Kälberserum : 1, Elektrophysiologische Messungen an den Oberflächenmembranen
    (1971) Hülser, Dieter F.; Frank, Werner
    Normal embryonic rat cells incubated in serum-free medium accumulate in G1-phase of the cell cycle. On addition of a growth stimulating protein isoIated from fetal calf serum they are triggered to proceed through the cycle and they resume DNA synthesis 15 to 20 hour later. In this paper it is demonstrated that the surface membrane potential difference (PD) decreases immediately after changing serum-free medium against culture medium containing either calf serum or the isolated serum protein; the original PD is restored 2 to 3 hours later. Serumprotein without growth-stimulating activity does not affect the PD. A permanent rat cell line which grows independently of serum also has been tested. The PD of these cells is not significantly influenced by calf serum.