高频电磁场对雌性大鼠海马细胞形态学的影响

Effects of high-frequency electromagnetic field on morphology of hippocampal ceils in female rats

目的研究短期及亚慢性暴露高频电磁场（HF—EMF，30MHz，电场强度0－1600V／m）对雌性大鼠海马细胞凋亡及超微结构的影响，探讨HF—EMF对雌性大鼠海马细胞损伤的作用。方法选用清洁级Wistar雌性大鼠120只，按体重随机分为10组，大鼠置于HF．EMF辐射源，频率30MHz，各组辐射剂量平均电场强度为0、25、100、400、1600V／m，短期实验是连续辐射8h／d，连续3d后取海马；亚慢性实验是8h／d，每周连续5d，停2d，共暴露56d后取海马，HE染色法光学显微镜下观察海马细胞病理改变，脱氧核苷酸转移酶介导的dUTP缺口末端标记法（TUNEL）系统检测海马细胞凋亡情况，电子显微镜下观察细胞的超微结构。结果（1）短期实验：各组大鼠海马细胞病理改变不明显，细胞凋亡率的差异无统计学意义（P〉O．05）。（2）亚慢性实验：与对照组（0．052％±0．016％）比较，400、1600V／m组DG区颗粒细胞凋亡率（分别为0．165％±0．049％、0．189％±0．049％）明显增加，差异有统计学意义（P〈0．01）；光学显微镜下可见，400、1600V／m组大鼠海马细胞核固缩明显增多，电子显微镜下可见，100V／m以上剂量组的神经元细胞超微结构有轻微改变，1600V／m组大鼠海马神经元细胞超微结构改变较明显。结论短期暴露HF—EMF（30MHz，25～1600V／m）对雌性大鼠海马细胞形态学影响不明显；亚慢性高剂量暴露HF—EMF（400～1600V／m）对大鼠海马细胞形态学影响较明显，低剂量暴露（25—100V／m）对大鼠海马细胞形态学影响不明显。

Objective To analyze the effects of high-frequency electromagnetic field （HF-EMF, 30 MHz, 0-1600 V/m） on the apoptosis and uhramicrostructure of the hippoeamp and demonstrate the cytotoxicity of hippocamp. Methods 120 Wistar female adult rats were randomly divided into ten groups based on body weight with different levels of 30 MHz electromagnetic field （0, 25, 100, 400, 1600 V/m） for eight hours daily. Five group rats were irradiated for three days. The other five group rats were irradiated for fifty-six days. Weekly the rats were continuously exposed five days. The apoptotic rate of the hippocamp was detected with TUNEL System. Meanwhile, the uhramicrostructure was observed with the transmission electron microscope. Results （ 1 ）There was no significant difference on the apoptotic rate and pathological change of the hip- pocamp cell between the exposure and the control groups through short term experiment （P〉0.05）. （2） The apoptotic rate of the granulocyte on the DG campus of the hippocamp in the 400 V/m group and the 1600 V/m group （0.165%±0.049%, 0.189%±0.049% respectively） were increased significantly （P〈0.01） through inferior chronic experiment compared with the control group （0.052%±0.016%）. Along with the increase of radiation dose, the ultramicrostructure of the neuron cell appeared more abnormal cells. Especially there were marked change on the neuron in the 1600 V/m group. Conclusions There is no association between cell apoptotic rate of the hippocamp and short period exposure to HF-EMF （30 MHz, 25-1600 V/m）. However inferior chronic exposures to HF-EMF might induce the cytotoxicity, especially in the high dose exposure （1600 V/m） under our experiment.