血管内放射治疗对平滑肌细胞增殖与凋亡的影响

目的：观察血管内放射治疗（简称放疗）对受损动脉平滑肌细胞（SMC）增殖与凋亡的影响。方法：用^192Ir后装源对猪受损髂动脉进行不同剂量血管内放疗，通过免疫组织化学增殖细胞核抗原（PCNA）与三磷酸脱氧尿嘧啶缺口末端标记法（TUNEL）检测不同时间点血管SMC增殖与凋亡情况。结果：放疗组第3天起中膜SMC增殖明显受抑及凋亡增加（P均＜0．05）；第10天时内膜SMC增殖明显减弱，20Gy组内膜SMC凋亡率显著增加；第28天时内膜SMC增殖明显受抑，凋亡率增加（P均＜0．05），20Gy组较10Gy组明显（P＜0．05）。结论：血管内放疗可抑制动脉损伤后SMC增殖、促进SMC凋亡。

Effects of intravascular irradiation on proliferation and apoptosis of smooth muscle cells

Objective To investigate the effect of intravascular irradiation on the proliferation and apoptosis of vascular smooth muscle cells(SMC) after arterial injury. Methods Twenty seven minipigs undertaking iliac artery balloon overstretch injury were given intravascular irradiation with 192 Ir at different doses. The pigs were killed at the 3rd, 10th or 28th day after operation for dynamic observation, respectively. SMC proliferation of injured segments was examined using proliferation cell nuclear antigen (PCNA) assessment, while apoptosis was examined using terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL). Results Compared with the control group, medial SMC proliferation was inhibited and apoptosis was significantly increased in the 10 and 20 Gy irradiation group from the 3rd day ( P <0.05); the degree of neointimal SMC apoptosis in 20 Gy irradiation group was higher than that in control group at the 10th day( P <0.05); neointimal SMC proliferation was significantly inhibited and apoptosis was significantly increased both in the 10 and 20 Gy irradiation group at the 28th day( P <0.05). The effect was more apparent on inhibiting SMC proliferation and increasing apoptosis in 20 Gy group at the 28th day. Conclusions Intravascular gamma irradiation can inhibit SMC proliferation and stimulate SMC apoptosis in balloon injured arteries. These factors may contribute to the prevention of restenosis after arterial injury.