The effect of thalidomide on neointimal hyperplasia after balloon injury in rat carotid artery

Objective:To determine the inhibitory effect of locally delivered thalidomide on neointimal hyperplasia and restenosis after balloon injury in rat carotid artery and the possible mechanisms.Methods:48 male Sprague-Dawley rats were randomly divided into sham operation group(group A),operation group(group B)and operation with thalidomide group(group C).The carotid arteries of group B and group C were injured by conventional percutaneous transluminal coronary angioplasty(PTCA)balloon catheter.At 7 and 14 days after balloon injury,rats were killed sequentially.Serum concentrations of vascular endothelial growth factor(VEGF)and tumor necrosis factor-α(TNF-α)were measured by enzyme-linked immunosorbent assay(ELISA).Neointima area,lumen area,macrophage infiltration and local expressions of VEGF were measured by morphometric and immunohistochemical analyses.Results:The levels of VEGF and TNF-α at 7 days and 14 days after balloon injury were more significantly increased in group B than that in group A and C(P0.01).Thalidomide administration resulted in a significant reduction of neointimal formation 14 days after balloon injury(P0.01).Arterial macrophage infiltration and local expressions of VEGF in the injured arteries were significantly reduced by locally delivered thalidomide.Conclusion:Thalidomide,a specific agent for VEGF inhibition,significantly inhibited neointimal hyperplasia and vascular restenosis after balloon injury in rat carotid artery,which might provid a novel procedure for prevention and therapy of restenosis,especially in-stent restenosis.