1.8GHz微波对小鼠下丘脑组织结构的影响

Effect of 1.8 GHz Microwave on the Structure of Hypothalamus in Mice

旨在研究1.8 GHz的电磁辐射是否对性成熟前小鼠的下丘脑细胞产生形态学影响。试验选用90只昆白雌鼠,随机平均分为三组,从母鼠怀孕当天至小鼠出生后30 d采用1.8 GHz的电磁辐射,强度分别为0(对照组)、1(低剂量试验组)和2 mw·cm^-2(高剂量试验组)。观察仔鼠的精神状态,30、45、60日龄时取材,记录体重和脑质量,用组织学方法观察下丘脑组织结构的变化,采用高效液相色谱仪检测下丘脑中神经递质谷氨酸(Glu)、天门冬氨酸(Asp)、γ-氨基丁酸(GABA)和甘氨酸(Gly)的含量。结果显示,(1)30日龄时两试验组小鼠的体重、脑质量均显著减小(P<0.05),下丘脑细胞出现空泡化,细胞内线粒体水肿,血管间隙扩张,小鼠脑内Asp、Glu、Gly、GABA的含量均增加。(2)45日龄时,低剂量试验组细胞形态基本恢复,线粒体肿胀现象仍然存在,但脑内Asp、Gly、Glu、GABA的含量与对照组相比无明显差异(P>0.05);高剂量试验组细胞萎缩仍较多,细胞内线粒体肿胀,小鼠脑内Asp、Glu、Gly、GABA的含量显著增加(P<0.05)。(3)60日龄时,低剂量组细胞形态基本恢复,线粒体恢复正常,小鼠脑内Asp、Glu、Gly和GABA的含量与对照组相比无明显差异(P>0.05);高剂量组细胞基本恢复,细胞内线粒体肿胀基本恢复,细胞核恢复正常形态,脑内Asp、Glu、GABA的含量与对照组相比无明显差异(P>0.05),但Gly的含量与对照组相比显著增加(P<0.05)。结果表明,1.8 GHz微波辐射处理可对小鼠下丘脑的细胞形态和功能产生一定损害,但停止辐射后,下丘脑的细胞形态和功能可逐渐恢复。

The aim of this study was to investigate the morphological changes of hypothalamic cells in pre-puberty mice exposed to electromagnetic radiation at 1.8 GHz. The trial was randomly divided into three groups and each group consisted of 30 repetitions. Microwave irradiation frequency we used was 1.8 GHz and three groups were treated respectively on 0(Control group), 1(Low dose test group) and 2 mw·cm^-2(High dose test group). Radiation was made on maternal mice during the entire period of gestation and lactation, and on the offspring until the day of postnatal 30. The mental state of mice were observed. The body mass, the cerebral mass of mice was recorded. Brain samples were collected at 30, 45 and 60 days of age. The histological changes of the hypothalamus were observed. The contents of neurotransmitter glutamate(Glu), aspartic acid(Asp), γ-aminobutyric acid(GABA) and glycine(Gly) in the hypothalamus were detected by HPLC. Results were as follows:(1) At the age of 30 days, the results showed that the body weight and brain weight in two experimental groups were lower than that of the control group(P<0.05), and the content of Asp, Glu, Gly and GABA in the brain of mice increased. Changes of ultrastructure including vacuolization in the hypothalamic cells, intracellular mitochondria edema, and dilated vascular space.(2) At the age of 45 days, the morphology of the cells in the low-dose test group recovered, but mitochondrial swelling still existed. Besides, the level of Asp and Gly in the brain decreased(P>0.05), and the level of Glu and GABA increased(P>0.05). In the high-dose test group, massive atrophic cells and swollen intracellular mitochondria still could be observed, and the content of Asp, Glu, Gly and GABA in the brain increased(P<0.05).(3) At the age of 60 days, the morphology of the cells in the low-dose group recovered. The mitochondria returned to normal, and there was no significant difference of the content of Asp, Glu, Gly and GABA in the brain between two groups(P>0.05). In the high-dose group, the hypothalamic cells basically recovered. Swollen mitochondria was nearly repaired and the nuclear was the normal appearance. The concentration of Asp in the brain decreased, and the concentration of Glu, GABA, and Gly increased. Overall, radiation damages the hypothalamic cells in mice, and these damages could be restored after radiation stops.