The Effect Of Trapidil On Intimal Hyperplasia Of Autografted Vein Of Rats

Objective: To investigate the prevention of Trapidil on intimal hyperplasia of autografted vein of rats, then discuss its potential mechanism.Methods: The establishment of autografted venous model was used with external jugular vein- arteria carotis transplantation in rats. According to the administration condition after autografted venous transplantation,120 SD rats were randomly classified into three groups:the control group(A) low dose Trapidil-treated group(B)and high dose Trapidil-treated group(C).TxB2 and 6-K-PGF1 content in blood serum were detected before and 1 day after transplantation.At2,4,6,8 weeks after transplantation,the vein grafts were harvested to carry out histopathologic examination.The expression of PCNA were examined at 2 weeks and PDGF at 2,4,6,8 weeks post-transplantation. Ultramicrostructure change of vein grafts was observed and analyzed under electron microscope at 4 and 8 weeks post-transplantation.Results: The thickness of intima ,tunica media, ratio of tunica media area to intima and lumina stenosis fraction significantly decreased in high-dose Trapidil treated group compared to the control(P<0.05)and low-dose Trapidil treated group(P<0.05).The seru concentration of TxB2 of high-dose Trapidil treated group was significantly lower than that of the control(P<0.05)and low-dose Trapidil treated group(P<0.05),when seru 6-K-PGF1 content was compared, the high-dose Trapidil treated group was significantly higher than the control(P<0.05)and low-dose Trapidil treated group(P<0.05),and TxB2/6-K-PGF1 in high-dose Trapidil treated group was lower than in the control (P<0.05) and low-dose Trapidil treated group( p<0.05).At 8 weeks post-transplantation the expression of PCNA At 2 weeks and PDGF-A at 2,4,6,8 weeks post-transplantation significantly decreased in high-dose Trapidil treated group compared to the control (p<0.05)and low-dose Trapidil treated group(p <0.05). Proliferation of vascular smooth muscular cells, extracellular matrix apposition and inflammatory cell infiltration were obviously improved in Trapidil treated group, and the structure of grafted veins were more integrated than control group, less ultramicrostructural injury of vein grafts was observed in high-dose group.Conclusion: Trapidil can degrades autografted vein intimal hyperplasia, restrains vascular smooth muscle cell migration to intima and vascular smooth muscle cell proliferation of tunica media, lessens extracellular matrix apposition and Inflammatory cell infiltration .The mechanism may relates with the inhibition of synthesis and activity of TxA2, promotion of PGI2 production and highly selective suppression of PDGF,then supresses vascular smooth muscular cell proliferation, synthesis and secretion of extra-cellular matrix and reduces inter-cellular adhesion and the expression of inflammatory factors.