Connective tissue activating macromolecules in macrophage culture medium.

Fractions isolated by isoelectric focusing (pI values 4.6-5.3) from macrophage culture media stimulated fibroblast proliferation in vitro and increased the synthesis of sulfated glycosaminoglycans (sGAGs). Cationic fractions from macrophage culture media isolated by the same procedure (pI 10.2-10.4) enhanced secretion of collagen by fibroblasts. Two dimensional electrophoresis of non-fractionated 3H-lysine labeled macrophage media only showed incorporation of label into acidic proteins. The fractions from the pI area which increased DNA and GAG synthesis by fibroblast cultures contained three major labeled proteins with molecular weights of 15 K, 25 K and 135 K.