[Effect of expression of c-myc gene on hyperplasia of smooth muscle cells in vein graft in rat].

OBJECTIVES

To analyse effect of expression of c-myc gene on hyperplasia of smooth muscle cells in vein graft and evaluate the effect of c-myc gene on intimal hyperplasia of vein grafts.

METHODS

We transplanted the autologous internal jugular vein on iliac artery by end to end anastomosis in rat. The vein grafts were harvested at 30 min, 2 h, 6 h, 2 days, 1 week, 2 weeks and 4 weeks after grafting and were rapidly frozen in liquid nitrogen. Proteins of PCNA and c-myc were detected in the different time with method of immunohistochemical staining (SP) and c-myc mRNA with in situ hybridization. Staining result was measured by microscope (400X).

RESULTS

Freshly harvested veins did not demonstrate PCNA, c-myc protein production and c-myc mRNA. Staining for c-myc mRNA was significantly higher at 2 h, 6 h compared with that at 30 min (P < 0.01). Staining for PCNA, c-myc protein production peaked at 1 week (44.8 +/- 8.2)%, (16.2 +/- 3.2)%, respectively) and was significantly higher than that at 6 h (3.2 +/- 0.7)%, (4.1 +/- 0.9)%, respectively) (P < 0.01).

CONCLUSION

c-myc is expressed early after experimental vein grafting, with peak at 1 week paralleled with PCNA. This occurs during a period of maximal SMC proliferation, and increased expression of PCNA. Expression of c-myc gene may contribute to the induction and regulation of SMC proliferation.