EFFECT OF ALL-TRANS RETINOIC ACID ON PROLIFERATION OF VASCULAR SMOOTH MUSCLE CELLS AND THE EXPRESSION OF AKT1 IN RABBIT CAROTID ATHEROSCLEROSIS LESIONS

Objective To investigate the influence of all-trans retinoic acid (atRA) on intima proliferation and expressions of AKT1 and PCNA in rabbit carotid artery after endomembrane injury.MethodsThirty-six New Zealand rabbits wereevenly randomized to six groups:sham-operation group A and group B; operation group A and group B; and treatment group A and group B. All the rabbits were fed with high fat diet for 14 days. A model of carotid artery endomembrane injury was created in operation group. In treatment groups, rabbits were lavaged with atRA daily for 3 days before operation. Those in sham-operation groups underwent surgery without injuring the endomembrane. Rabbits in groups A were killed 7 days after operation and those in groups B, 28 days. Carotid specimens were taken for gross examination and immunohistochemistry study used for detection of the expressions of AKT1 and PCNA proteins. ResultsSeven days after operation, neointima formation was found in carotid artery in the operation group, and it became obvious afetr 28 days with atherosclerosis plaque, narrowing of arterial lumen and expressions of AKT1 and PCNA. In the treatment group, there was mild intima proliferation, and, 28 days after surgery, the intima area was smaller and the plague was thinner than that of the operation group (t=3.797, 3.704;P0.01). The index of positive expressions of AKT1 and PCNA in the treatment group was also lower than that of the operation group (t=4.741, 2.890;P0.05). ConclusionatRA can suppress the expressions of AKT1 and PCNA in injured endomembrane of rabbit carotid artery, inhibit the proliferation of vascular smooth muscle cells, and therefore inhibit neointima proliferation and progression of atherosclerosis.