Attachment of smooth muscle cells to collagen and their migration toward platelet-derived growth factor.

Smooth muscle cells use fibronectin to bind to type I and type III collagens but bind to type V collagen by a trypsin-resistant intrinsic glycoconjugate. The binding site on type V collagen is located in the alpha A chain. By using collagen-coated filters in a modified Boyden chamber assay for chemotaxis, it was observed that the platelet-derived growth factor was chemotactic for smooth muscle cells but that several other growth factors were inactive. We suggest that the migration of smooth muscle cells from the media to the intima of a blood vessel, which leads to the formation of an atherosclerotic plaque, may be the result of a chemotactic migration of cells responsive to the platelet-derived growth factor.