Effects of All-trans Retinoic Acid on Vascular Remodeling and VEGF Expression in Rabbit Carotid Artery after Endothelium Injury

Objective To evaluate the influence of all-trans retinoic acid(atRA)on intimal prolif- eration and VEGF expression in carotid endothelial injury in rabbits and its mechanisms.Methods 36 New Zealand rabbits were randomly divided into 6 groups:treatment group(A,B),control group(A,B), sham-operation group(A,B).There were 6 rabbits in each group.The rabbits in the treatment groups and the control groups were fed with high cholesterol chow and subject to the carotid endothelial injury by air des- iccation after 2 weeks.The sham-operation groups were fed with conventional chow,underwent surgery with- out endothelium injury.AtRA was administered daily to the treatment groups by gavagns.The rabbits in the A groups and B groups were sacrificed respectively at 7 and 28 days after surgery.The carotid artery seg- ments were harvested for histomorphometry observation.Immunohistochemistry were used to detect VEGF and PCNA protein.Results The VEGF and PCNA expression of control groups were significantly upregulat- ed,neointimal formation was found in carotid artery at 7 days after injury and severe intima thickness,ather- osclerosis was found at 28 days in the control group.In the treatment group,the intimal area,intimal/medial area ratio and maximum plague thickness of the artery at 28 days after surgery were lower than the control group,(P0.001;P0.001;P0.05),the expression of VEGF and PCNA were lower too(P0.01, P0.001 respectively).Conclusion The results indicate that atRA can suppress the VEGF and PCNA ex- pression in endothelium injured artery,inhibit neointimal proliferation and atherosclerosis progression.