γ射线对血管平滑肌细胞增殖的影响

Effect of γ-Irradiation on the Proliferation of Vascular Smooth Muscle Cells

目的 :了解γ射线对血管平滑肌细胞 (SMC)增殖的影响及剂量—效应关系。方法 :在无菌条件下取猪的胸主动脉 ,用组织块贴壁法培养SMC ,取进入指数生长期的猪主动脉SMC分别用 0Gy、3 5Gy、7 0Gy、14 0Gy、2 8 0Gyγ射线照射 ,用3 H标记的胸腺嘧啶核苷 ( 3 H TdR)掺入试验分别在照射后 12h、2 4h、36h、48h测SMC的3 H TdR掺入量 (以每分闪烁计数值表示 ) ,同时观察细胞形态的变化。结果 :不同照射剂量在各时点3 H TdR掺入量均较照射剂量为 0Gy时明显减少 (P <0 0 5 ) ,γ射线对SMC增殖的抑制作用为 7 0Gy及 14 0Gy >3 5Gy ,而 2 8 0Gy抑制作用最强。形态学观察发现各组细胞轮廓明显增强 ,胞浆中可见颗粒状物质 ,14 0Gy照射细胞时出现空泡样变 ,照射剂量 2 8 0Gy可见大量细胞死亡。结论 :γ射线 ( 3 5Gy～ 2 8 0Gy)能明显抑制SMC增殖 ,且抑制作用随剂量增大而增强 ;照射剂量 <14 0Gy时以细胞抑制作用为主 ,照射剂量 2 8

Objective:To examine the effect of γ-irradiation on the proliferation of vascular smooth muscle cells(SMC)and its dose response relationship. Methods:The thoracic aortas of pigs was obtained under sterile condition and their vascular smooth muscle cells were isolated and cultured by tissue explantation technique.When the cells were in exponential growth phase,they underwent γ-irradiation of 0 Gy,3.5 Gy,7.0 Gy,14.0 Gy,28.0 Gy,respectively.Twelve,24,36,48 hours after irradiation,proliferation degree was measured with 3H-thymidine( 3H-TdR)incorporation method.Morphological changes were also observed. Results:Intake of 3H-TdR of all the irradiated groups was significantly lower than that of the control group at each time point(p<0.001).The inhibitory effect of 7.0 Gy and 14.0 Gy was greater than that of the 3.5 Gy(p<0.05),whereas the inhibitory effect of 28.0 Gy was the most prominant(p<0.05).Morphological examination showed that the cells of the irradiated groups had more distinct outlines,and there was particulate matter in cytoplasm.Vacuolar degeneration and dead cells were observed in cells of 14.0 Gy and 28.0 Gy groups. Conclusion:γ-irradiation of 3.5 Gy-28.0 Gy can significantly inhibit the proliferation of vascular SMC and the inhibitory effect is dose-dependent.When the dose at ≤14.0 Gy,the inhibitory effect is dominant.However when the dose is 28.0 Gy,the lethal effect is mainly observed.