Inhibition of growth factor binding and intracellular Ca2+ signalling by dextran sulfates of different sizes and degrees of sulfation.

The ability of dextran sulfates of varying molecular sizes (5-500 kDa) and degrees of sulfate substitution (0.3-1.9) to inhibit the binding of platelet-derived growth factor (PDGF) to intact Swiss 3T3 fibroblasts and to inhibit inositol(1,4,5)trisphosphate-dependent release of Ca2+ in permeabilized Swiss 3T3 cells was examined in the present study. Significant correlations were found between increased molecular size of the dextran sulfates and inhibition of both PDGF binding (r = 0.77) and Ca2+ release (r = 0.72). The degree of sulfate substitution did not correlate with inhibition of either activity.