Effects of tranilast on neointimal proliferation and remodeling of rabbit iliac artery after balloon injury

Objective To evaluate the effect of tranilast on neointimal proliferation and remodeling of rabbit iliac artery after balloon injury.Methods Twenty four rabbits were randomly divided into 3 groups including sham-operated group, control group, and treatment group. Balloon catheter was used to induce injury to the iliac artery of rabbits in control group and treatment group. Tranilast was given to the rabbits in treatment group (300 mg·kg -1) once a day from 3 days before operation to 28 days after operation, and then local vessels were harvested for pathological analysis and immunohistochemical staining. Automatic image analysis system was used to detect the changes of intimal thickness, medial thickness, luminal area, external elastic lamina (EEL) cross-sectional area and the proliferation index of proliferating cell nuclear antigen (PCNA). Results The intimal thickness was decreased in treatment group compared with control group. The luminal area and EEL cross-sectional area were significantly larger in treatment group than those in control group. No significant difference was found between treatment group and control group in medial thickness. The proliferation index of PCNA was significantly reduced in treatment group compared with control group. Conclusions Tranilast signifcantly inhibited neointimal hyperplasia and prompted compensatory artery dilation during remodeling of rabbit iliac artery after balloon injury. The effect on neointimal hyperplasia may be partly attributed to the inhibition of vascular smooth muscle cell proliferation.