Cell density regulates the number of cell surface receptors for fibroblast growth factor.
Previous studies have shown that the binding of fibroblast growth factor to several different non-transformed cell lines decreases as cell density increases. However, it was not determined whether this is due to a reduction in receptor number or to a decrease in receptor affinity. In this study, we demonstrate that the reduction in fibroblast growth factor binding is due to a reduction in receptor number. In addition, flow cytometric analysis indicated little or no difference in the cell cycle distribution of the cells at low and high cell densities, yet the binding of fibroblast growth factor was reduced substantially at high cell densities. Thus, the reduction in growth factor binding observed in this study does not appear to result from cell cycle-dependent regulation of growth factor receptors.
Veomett
G
G
Eppley Institute, University of Nebraska Medical Center, Omaha 68105-1065.
Kuszynski
C
C
Kazakoff
P
P
Rizzino
A
A
D000818:Animals; D002452:Cell Count; D002453:Cell Cycle; D002460:Cell Line; D005346:Fibroblast Growth Factors / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D005434:Flow Cytometry; D051381:Rats; D011956:Receptors, Cell Surface / Q000032:analysis*; D017468:Receptors, Fibroblast Growth Factor
D011956:Receptors, Cell Surface; D017468:Receptors, Fibroblast Growth Factor; D005346:Fibroblast Growth Factors