Trapidil Inhibits Endothelial Cell Proliferation and Angiogenesis in the Chick Chorioallantoic Membrane and in the Rat Cornea

The effects of trapidil, a coronaro-active drug which has been shown to inhibit the mitogenic activity of platelet derived growth factor (PDGF), have been investigated on the proliferation of the human endothelial cells (HW-EC-C), on the neovascularization in the chorioallantoic membrane of the chick embryo (CAM) as well as on the angiogenesis of rat cornea following chemical injury. The proliferation of HW-EC-C in the presence of trapidil (25 and 250 mu g/mL) was significantly inhibited by 19 and 25% respectively, compared to controls. On 2-days old CAMs, agarose disks containing 190-150 mu g of trapidil produced an avascular zone indicating significant antiangiogenic activity, while control agarose disks were without effect. Corneal neovascularization was induced by applying a silver nitrate/potassium nitrate applicator to the rat eyes. A 6-day-treatment with eye drops of a solution of 10 mg/mL trapidil. significantly decreased the rate of vessel growth compared with vehicle controls. The antiangiogenic activity of trapidil was markedly increased by the association with hydrocortisone (1.34 mg/mL). These results suggest that trapidil, alone or in combination with a steroid, could be a promising candidate for the therapy of corneal diseases in which alterations induced by neovascular growth play a substantial role.