A platelet-derived factor chemotactic for rabbit arterial smooth muscle cells in culture

Following endothelial injury in a blood vessel, intimal proliferation of smooth muscle cells is preceeded by platelet adherence to the subendothelium and migration of cells from the media. Factors released from platelets were examined for their ability to induce directed migration of smooth muscle cells across a filter in a modified Boyden chamber. Thrombin and collagen induced the release of a nondialysable, heat stable chemotactic factor from washed rabbit platelets. Release of this factor does not depend on primary aggregation but is associated with the release reaction and is independent of products derived from the metabolism of arachidonic acid. Directed migration of the smooth muscle cells in response to the platelet-derived chemotactic factor does not require the presence of serum.