Heparan sulfate fractions: pharmacological properties and effect on smooth muscle cell proliferation in vitro

In this study we have evaluated the effect of heparan sulfate fractions with different molecular weights on the growth of aortic smooth muscle cells (SMC) of rat in vitro. These fractions were obtained from unfractionated heparan sulfate by a gel filtration technique. The fraction having a molecular weight of 25.5 kDa showed a significant antiproliferative activity only at higher concentrations, while the fractions with molecular weight ranging from 10.7 kDa to 6.8 kDa were effective in reducing cell proliferation at very low concentrations (10(-5) nM and 10(-4) nM). The dose-effect curves are characterized by an initial plateau followed by an increase in effectiveness at the highest concentration. The relationship between molecular weight and antiproliferative activity is discussed.