Expression of extracellular signal-regulated kinases in autogenous vein graft

Objective To investigate the gene expression of extracellular signal-regulated kinases (ERKs) in autogenous vein graft in rats. Methods Autogenous vein graft model was established by transplanting the right jugular vein to infrarenal abdominal aorta in 80 Wistar rats. Vein graft samples were harvested 6 h, 24 h, 3 days, 7 days, 2 weeks, 4 weeks, 6 weeks and 8 weeks after surgery. The ex- pression of ERK1 mRNA was detected by reverse transcription-PCR and in situ hybridization. Western blot and immunohistochemistry methods were used to detect the protein production and phosphorylation of ERKs. Proliferating cell nuclear antigen (PCNA) also was studied. Results The expression of ERK1 mRNA was increased quickly after surgery and reached the peak on 7th day [ (33. 2 ± 14. 2)%, P 0.01 as compared normal other time points] and returned to normal levels 4 weeks after surgery. The expres- sion of ERK1/2 detected by western blot reached the peak during 1 to 2 weeks and was decreased gradu- ally to normal level 6 weeks after surgery. The positive cells were mostly vascular smooth muscle cells (VSMCs) located in media and intimal hyperplasia of vein graft. There was a positive relationship be- tween ERK1 and PCNA(r = 0. 759 6, P 0. 01). Conclusion The activation of ERKs present in auto- genous vein graft may become a new target for the therapy of intimal hyperplasia and stenosis after vein graft.