【作者】 丁建松；

【导师】 童建；

【作者基本信息】 苏州大学 ， 卫生毒理学， 2007， 硕士

【摘要】 随着手机应用的日益广泛,有关微波辐射对人体健康影响的报道不断增多。流行病学研究和动物实验均表明手机辐射会对生物体产生广谱效应,但迄今为止作用机制仍不明确。目的:建立900MHz连续微波对鸡胚效应的研究模型,采用物理和生化指标探讨其对鸡胚发育的影响,为揭示微波的生物效应机制提供基础性资料。方法:(1)微波照射方法:各照射组正常发育之鸡胚于孵化第5天(day,d)整体接受900MHz连续微波功率源照射,功率密度约为1.5mW/cm2,每天分别照射1、2、4h。(2)物理指标测定:采用体外无损检测鸡胚发育过程中心电图的方法,探讨微波对鸡胚心率和QRS影响;利用超微弱发光测量仪测定鸡胚超微弱发光,以观察微波对生物体内部电磁场的干扰情况;并对鸡胚孵化率和出壳后小鸡体重、自发活动度进行测定。(3)化学指标测定:采用黄嘌呤氧化酶法-羟胺法测定各组鸡胚心脏、脑组织匀浆超氧化物歧化酶(superoxide dismutase,SOD)活性;RT-PCR法测定鸡胚发育过程中心脏、脑组织匀浆热休克70KD蛋白(Heat Shock Protein 70,Hsp70)mRNA水平; NGO分光光度法测定鸡胚脑组织匀浆鸟氨酸脱羧酶( orinithine decarboxylase,ODC)活性。结果:(1)微波对鸡胚SOD、ODC活性和Hsp70mRNA水平影响:在鸡胚发育13d,900MHz连续微波照射可引起2h照射组鸡胚脑组织和4h照射组鸡胚心脏、脑组织SOD活性显著降低,亦可致2h、4h照射组鸡胚心脏、脑组织Hsp70 mRNA水平显著升高;而在20d,照射组鸡胚各指标与对照组相比均无显著变化。(2)微波对鸡胚心电图(electrocardiogram,ECG)影响:从15d开始可记录到较为清晰的心电图。在鸡胚发育15d,微波辐射未引起鸡胚心率显著改变;在17d,1h照射组鸡胚的心率显著降低;在20d,4h照射组鸡胚心率显著降低。各照射组鸡胚的QRS间期无显著变化。(3)微波对鸡胚孵化率、超微弱发光的影响:未观察到微波辐射对鸡胚孵化率的显著影响。在鸡胚发育16d,1h和2h照射组鸡胚超微弱发光显著降低,但在13d和20d各组鸡胚无显著变化。(4)微波对出壳小鸡体重和自发活动的影响:在出壳后1d,各照射组小鸡体重与对照组比较无显著差异,而小鸡自发活动在1h和2h照射组增强;出壳后10d,照射组小鸡体重已经显著高于对照组,自发活动恢复至正常水平。结论:900MHz微波对发育期鸡胚的作用存在窗效应,可致鸡胚心率降低,鸡胚心脏、脑组织抗氧化系统稳态一过性失衡,并出现热休克反应。随着发育的不断成熟,损伤可以恢复,鸡胚对微波的耐受性逐渐增强。更多还原

【Abstract】 Cellular phones are rapidly gaining popularity and yet little is known about the health hazards of the microwave by use of the phones. The public have become increasingly concerned about the health impact shown by the non-thermal effect from animal experiments and epidemiologic studies.Objective:To study with the chick embryo model for biological effects of 900MHz continuous microwave and to provide with basic data for exploring mechanisms of the adverse effects of microwave from celluar phones.Metheods:(1)Irradiation method: Chick embryos of three dose groups were exposed to 900MHz continuous radiofrequency fields from 5thday to 20th day of incubation, with 1h, 2h and 4h per day. The power density was 1.5mW/cm2. (2)Measurement of physical parameters: A noninvasive technique of recording electrocardiogram (ECG) from chick embryos was established. Heart rates and QRS intervals were determined by the ECG. Ultraweak luminescence of embryos was measured by the UltraWeak Luminescence Analyzer. Besides, spontaneous movements and weights of hatched chicks were recorded, so was the hatching rate of chick embryos. (3)SOD(superoxide dismutase) activity in heart and brain tissue was dectected by method of xanthine oxidase- hydroxylamine. Reverse transcription polymerase chain reaction(RT-PCR) was conducted to examine levels of Hsp70 mRNA in heart and brain tissue.Results:(1)On the 13th day of incubation, the SOD activity in brain tissue of 2h irradiation group was significantly decreased compared to the control group, so was the SOD activity in heart and brain tissues of 4h irradiation group. Levels of Hsp70mRNA in heart and brain tissue of 2h and 4h irradiation group were found significantly increased. However, on the 20 th day, the SOD and ODC activity and level of Hsp70mRNA did not change obviously(.2)Compared to the control group, heart rates of three irradiation groups showed no changes on the 15th day. In 1h irradiation group on the 17th day and 4h irradiation group on the 20th day, the heart rate of chick embryos decreased significantly.(3)Though ultraweak luminescence of 1h and 2h irradiation group was decreased significantly on the 16th day of incubation, no distinct changes were found on the 13th day and the 20th day.(4)The spontaneous movement of chicks of 1h and 2h irradiation group increased significantly on the 1st day after hatching, and turned to normal on the 10th day. The weight of hatched chicks significantly increased in 1h and 4h irradiation group on the 10th day,but not on the 1st day.Conclusion: The results proposed a possible window effect of microwave on the chick embryos. The imbalance of antioxidation sytem and the heat shock reaction induced by the microwave could get recovery along with the development of chick embryos.更多还原