Influence Of All-trans Retinoic Acid On The Expression Of Cdk2, C-myc And The Proliferation Of Vascular Smooth Muscle Cells In Carotid Atherosclerosis In Rabbits

Objective: To investigate the influence of all-trans retinoic acid (ATRA) on the process of neointimal formation, vascular remodeling, the expression of Cdk2 and C-myc in carotid atherosclerosis in rabbits.Methods: Thirty-six New Zealand rabbits were randomly divided into 3 groups: normal group(n=12), control group(n=12), and ATRA-treated group(n=12). Control group and ATRA-treated group were fed by high-cholesterol diet and the two groups were made into carotid atherosclerosis model using air-drying after two weeks. ATRA-treated group were predosed with ATRA by gavage 3 days before surgery. All rabbits were killed one week and four weeks after surgery. After the target vessels were harvested, we used unmunohistochemistry staining to measure the protein expression of Cdk2, C-myc and proliferating cell nuclear antigen PCNA. Meanwhile vessel morphological measurement were taken.Results: â‘  In normal group, Cdk2, c-myc and PCNA were not detected. â‘¡ In control group, there were distinct neointimal formation and narrow luminal area in six weeks and the expression of PCNA, Cdk2 and C-myc were significantly high. â‘¢ In ATRA-treated group, the expression of PCNA, Cdk2 and c-myc were significantly lower than control group, ATRA-treated group had an outstanding smaller neointima/media area ratio and larger luminal area. â‘£The expression of PCNA and Cdk2, C-myc are in remarkable positive correlation.Conclusion: Inhibiting VSMCs proliferation by inhibiting the expression of Cdk2 and C-myc may be one mechanism by which ATRA reduced neointimal formation and elicited favorable geometric remodeling of the carotid atherosclerosis in rabbits.