Abstract:Aim To investigate the inhibitory effect of Cilostazol on matrix metalloproteinase-2 (MMP-2) and MMP-9 and tissue metalloproteinase inhibitor-1 (TIMP-1)and TIMP-2 protein and mRNA expression, to study its role and mechanism on proliferation after angioplasty. Methods 40 Japanese male white rabbits were injuried two times to make PTA models and divided into three groups: control group, high cholesterol group and Cilostazol group. PTA was proceeded under X-Ray, 4 weeks after the angioplasty, the damaged segments of abdominal arteries were harvested for morphometry (assessing NIA, MA, CA)and for immunohistochemical analysis as well as RT-PCR to evaluate MMP-2, MMP-9 and TIMP-1, TIMP-2 protein and mRNA expression level. Results Cilostazol can reduce the NIA and increase the CA. MMP-2, MMP-9 and TIMP-1, TIMP-2 protein and mRNA expression levels in high cholesterol control group increases at 4 th week after angioplasty. However, Cilostazol can reduce their levels. Conclusions Cilostazol can inhibit the vascular intimal hyperplasia, through its effect on the expression of MMP and TIMP to regulate the extracellular matrix turnover.