低强度微波辐射对兔髂外动脉损伤后再狭窄的影响

Irradiating Effect of Low Intensive Microwave on Restenosis of External Iliac Artery of Rabbit after Injury

目的探讨低强度微波(LIM)辐射对血管再狭窄病理过程的影响,以评价LIM辐射防治再狭窄的可能性。方法健康雄性新西兰大白兔48只,随机分为2组。应用Fogarty导管损伤兔髂外动脉(EIA)内膜,建立再狭窄动物模型。辐射组采用2 450 MHz微波,功率分别为2、5和10 mW/cm2,局部辐射EIA(1 h/d)。分别于术后3、7、14及28 d取材。采用HE和EF染色,观察EIA形态学改变及内膜面积、中膜面积及管腔狭窄率;TUNEL标记法检测细胞凋亡;TEM观察血管平滑肌细胞(VSMC)表型及超微结构。结果LIM微波辐射后,再狭窄早期炎症反应受到抑制,附壁血栓减少,各时间点VSMC的增殖、迁移被抑制,内膜面积和管腔狭窄率显著低于对照组(P<0.01)。细胞凋亡率在术后3 d各组间差异无统计学意义(P>0.05),其余时间点,辐射组显著高于对照组(P<0.01),其中5 mW/cm2者细胞凋亡率明显高于其他各组(P<0.01)。TEM观察到对照组大量合成型VSMC术后14 d达(93.50+3.45)%,辐射组VSMC以收缩型为主,大量成纤维细胞和VSMC呈凋亡的形态学改变。结论LIM辐射能显著抑制再狭窄病理过程中的早期炎症反应和VSMC的增殖、迁移,促进细胞凋亡,有效抑制再狭窄的发生、发展。LIM辐射存在量效关系和功率窗效应,功率强度为5 mW/cm2时对再狭窄的效应最强。

Objective To investigate the irradiating effect of low intensive microwave （LIM） on pathological process of blood vessel restenosis（RS） and assess the probability of LIM irradiation to prevent was used RS. Methods Forty-four male healthy New Zealand rabbits were randomly divided into 2 groups. Fogarty catheter traumatize to the tunica intima of iliac artery so as to establish RS models. Two thousand four hundred and fifty MHz microwave with different power of 2 ,5 and 10 mW/cm^2 was used, locally to irradiate EIA in irradiating group （1 h/d）. Specimens were obtained at different time of 3,7,14 and 28 d after operation. Morphological changes of tissues were observed with HE and EF staining and the area of tunica intima, tunica media and the rate of cavity stenosis were analyzed with image analysis system; apoptosis was detected with TUNEL; phenotype and microstructure of VSMC were observed with TEM. Results After microwave irradiating, intlammatory reaction in early period was suppressed, mural thrombus decreased, the proliferation and migration of VSMC depressed, the area of tunica intima and the rate of cavity stenosis obviously reduced comparing with the control group （P〈0.01）. The rate of apoptosis cells showed that there were no obvious differences among each group on 3 d after operation （P〉0. 05）. At other different time, however, the rate of apoptosis cells in irradiating groups obviously increased than that of the control group （P〈0. 01）, particularly in the one with power of 5 mW/cm^2. The number of synthesis form VSMC in the control group occupied （93.50±3.45） % of the total number of VSMC on 14 d after operation. Most of VSMC appear contractile in irradiating group in which a lot of morphological changes of apoptosis in fibroblast and VSMC existed. Conclusion LIM irradiation could obviously prevented from pathologic procedure of RS. After LIM irradiating, inflammatory reaction in early period is suppressed, the proliferation and migration of VSMC depressed. LIM irradiation promotes cell apoptosis, effectively prohibites the occurring and development of RS. LIM irradiation has had relationship between quantity and effect, power span to effectively prohibit RS, particularly in the one with power of 5 mW/cm^2.