Effect of valsartan on intima hyperplasia and expression of matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-2 in rabbit autologous vein graft

Objective To investigate the effect of valsartan on intimal hyperplasia,the expression of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2) in neointima,and to explain its mechanism of preventing stenosis in rabbit autotogous vein grafts.Methods Twenty male New Zealand rabbits were randomly divided into control group and treatment group with 10 in each.The rabbits underwent the operation of grafting external jugular veins into carotid arteries.The control group was fed with common feed,whereas the treat- ment group was fed with an admixture of valsartan 10mg/(kg·d) and common feed.Four weeks after the operation, the grafted veins were taken out for pathomorphologic examination.Thickness and area of the intima and media of the vein were calculated with image analyzer system,and expression of MMP-2,TIMP-2 in veins were examined with im- munohistochemistry reagent kits.Results Compared with the control group,the neointimal thickness and area were reduced in the treatment group.In the treatment group,the expression of MMP-2 was significantly lower while the expression of TIMP-2 was significantly higher than those in the control group.Conclusion Valsartan has remarkable inhibiting effects on intimal hyperplasia in rabbit autologous vein grafts.The mechanism may be related with the decrease in level of MMP-2 and the increase in level of TIMP-2 in vein grafts.