Apoptosis And Proliferation In Smooth Muscle Cells Of Autogenous Vein Graftin Rat Experimental Model

ObjectiveAutogenous vein transplantation is an effective method of treating coronary and peripheral artery occlusive diseases, but the stenosis of vein graft after replacement is the key problem which affects the long - term results. The mechanism of vein graft stenosis remains unclear. According to recently evidence, there is smooth muscle cells ( SMCs ) apoptosis in the intimal hyperplasia after vascular injuty, but the role of SMCs apoptosis in vein graft is undetermined. To evaluate the effect of apoptosis during neointimal formation in autogenous vein graft, apoptosis of smooth muscle cells in vein graft and its relationship with proliferation is observed at different time after transplantation, and expression of apoptosis associated genes in SMCs were also investigated.MethodsA rat experimental model of autogenous vein graft was established by transplanting the right external carotid vein into infrarenal abdominal aorta in 60 rats. The vein grafts were harvested at different time from 1 to 8 weeks. In order to eveluated proliferation and apoptosis during the neointimal formation. , immunohistochem - ical techniqueand TUNEL were used to detect proliferation and apoptosis in different time after replacement.ResultThere were only a little positive cells in the control veins by means of TUNEL. From 1 to 8 weeks, apoptosis of SMCs in vein graft could be detected by means of HE and TUNEL. The positive cell percentage of apoptosis was significantly higher than the controls. The expression of Ki - 67 after replacement was also significantly higher than the controls (p <0. 05). In 1 to 2 weeks, expression of both TUNEL and Ki - 67 reached peak, and the positive cell percentage of TUNEL was lower than that of Ki - 67, but in 4 to 8 weeks, the positive cell percentage of TUNEL was more than that of Ki - 67. From 1 to 8 weeks, the positive cell percentages of TUNEL and Ki - 67 were correlative(r= 0. 813, p<0. 05).ConclusionsProliferation and apoptosis in SMCs of vein graft coexist after autogenous vein replacement, and had significant correlation, these indicated that both proliferation and apoptosis of SMCs participated the process of vascular remodeling. The unbalance of proliferation and apoptosis may relate to the vein graft stenosis, and the conjunctive strategy of regulate the balance of proliferation and apoptosis may be useful to prevent vein graft stenosis.