Platelets stimulate aortic smooth muscle cell migration in vitro. Involvement of 12-l-hydroxy-5,8,10,14-eicosatetraenoic acid

The migration of rat aortic smooth muscle cells was measured in modified Boyden chambers. Smooth muscle cells were motile in vitro and their migration was stimulated (time- and dose-dependently) by a platelet-derived factor. Treatment of platelets with indomethacin resulted in a significant increase in smooth muscle cell migration, whereas treatment with 5,8,11,14-eicosatetraenoic acid inhibited it. Purified 12-l-hydroxy-5,8,10,14-eicosatetraenoic acid at a very low concentration (6 × 10^-15-6 ×^-13 g/ml) significantly stimulated smooth muscle cell migration. The locomotion induced by 12-l-hydroxy-5,8,10,14-eicosatetraenoic acid was chemokinetic. These findings point to the physiological importance of a platelet 12-lipoxygenase product of arachidonic acid in the early phase of atherosclerosis.