Effects of ATRA on Intimal Proliferation and Expression of PDGF-BB after Thoracic Aorta Balloon Injury in Rats

Purpose To investigate the effect of all-trans retinoic acid (ATRA) on intimal proliferation and expression of platelet derived growth factor BB(PDGF-BB) after vascular injury in rats. Methods Make models of aortic endothelial denudation of rats by ballon catheter.Rats were randomly allocated into three groups;.Group 1 (n=24) were given vascular balloon injury.Group 2 (n=24) were given ATRA (30 mg/[kg·d]) into stomach from 4 days before injury to 28 days after injury.Group 3(n=24) served as contrals were killed at day 2,7,14,28 after operation,not given vascular balloon injury.Neointima area were calculated morphologically at day 2,7,14,28 after injury.The expression of PDGF-BB were measured by means of immunohistochemical technique and imagine analyzer. Results (1) The migration and proliferation of vascular smooth muscle cells (VSMCs) had not existed at day 2 after balloon injury and contral group.The thickening of intima had begun at day 7 after injury,and they were more significant at day 14.The proliferation of VSMCs decreased at day 28,but extracellular matrix increased and the intimal thickning continued.(2) The positive expression of PDGF-BB were found at day 2 after balloon injury and reached maximum at day 14. (3) When given ATRA,the neointimal area and the index of PDGF-BB expression reduced. Conclusions ATRA can effectively repress intima proliferation after vascular injury,which may be associated with inhibiting the proliferation of vascular smooth muscle cells through down regulating the expression of PDGF-BB.