抑制C—myc基因表达对移植血管狭窄的影响

目的观察放射菌素D对移植血管中C-myc基因表达及内膜增殖的影响。方法建立大鼠自体静脉移植模型，实验组分别于术前、术后应用不同剂量放射菌素D（0.015，0.15mg/kg），对照组仅做血管移植。分别于术后2h及1周切取移植静脉，应用原位杂交方法检测C-mycmRNA表达，应用计算机图像分析仪测量内膜厚度。结果高剂量组C-mycmRNA表达较对照组明显减少（6.5%，12.5%；P<0.01），移植血管内膜增殖受到明显抑制（18.7，28.5μm；P<0.01）。结论大剂量应用放射菌素D可以抑制C-mycmRNA表达，从而抑制移植血管内膜增殖。早期应答基因C-myc表达在诱导平滑肌细胞增殖中起着重要作用。

Effect of Inhibiting C-myc Gene on Graft Stenosis

Objective: To investigate the effect of inhibitng C-myc expression by actinomycin D on intimal hy-perplasia in vein graft. Methods: The vein graft model was established in rats. The different dises of actinomycin D (0.015 mg/kg; 0.15 mg/kg) were given just before and after operation. The vein grafts were harvested at 2 hrs and 1 week after grafting. C-myc mRNA was measured by in situ hybridization method. The intimal thickness was measured using a computerised image analysis system. Results: The expression of C-myc mRNA and the intimal thickness were both significantly reduced in large dose (0.15 mg/kg) group of actinomycin D, with 6.5%; 18.7 μm compared with control group in 12.5%; 28.5 μm respectively. Conclusion: Actinomycin D can inhibit expression of C-myc mRNA and intimal hyperplasia in graft. Expression of C-myc plays an important role in inducing proliferation of smooth muscle cell in vein graft.