Expression of c-myc protein in vascular smooth muscle cell of vein graft rabbits

Aim: To study the expression of c-myc oncogenes in vascular smooth muscle cell (VSMC) in vein graft. Methods: A total of 25 New Zealand rabbits were randomly divided into five groups with five rabbits in every group.External jugular vein was interposed between ipsilateral common carotid arteries.The vein grafts were harvested after 6 h,2 days,1 week,2 weeks,4weeks.Immunohistochemical labeling and morphologic analysis of vein graft sections were used to identify c-myc positive cells.Intimal and medial thicknesses of perfusion fixed vein grafts were measured with a computer digitized system. Results: Intimal and medial thicknesses peaked after 7 days were significantly thicker than the same region at 6 h after graft implantation( P0.01). While intimal and medial thicknesses after 2 weeks and 4 weeks had no difference compared to that of 1 week( P0.05). Expression for c-myc was significantly higher at 1 week compared to that of 6 h(P0.01).Subsequently,c-myc staining decreased with a significant peak at 1week(P0.01). Conclusion: Expression of c-myc protein may contribute to the induction and regulation VSMC proliferation producing intimal hyperplasia, and may be an earlier index to determine the intimal hyperplasia.