900MHz电磁辐射对体外培养大鼠海马神经干细胞超微结构的影响

摘要

Objective To investigate the effect of 900MHz electromagnetic radiation on the ultrastructure of rat hippocampal neural stem cells (NSCs) in vitro in order to provide basic materials for studying the biological effects of electromagnetic wave on the central nervous system. Methods Rat NSCs were divided into sham group, Radii group and Radi2 group, and they were respectively exposed to 900 MHz electromagnetic wave at power density of 0, 1, and 3mW/cm in vitro. Cells in Radii group and Radi2 group were sub-grouped according to the way radiation was given: continuous irradiation, in which cells were exposed on the second day after culture for 2h per day for 6 consecutive days; single exposure to irradiation, in which cells were exposed for 12h on the sixth day after the culture. The ultrastructural changes on the surface of the cells were observed with atomic force microscope (AFM), whereas the ultrastructural changes in the cells were observed with transmission electron microscope (TEM). Results After 900 MHz electromagnetic radiation, when compared with the sham group (OmW/cm2), it was shown that the surface of neural stem cells in the exposure groups (l and 3mW/cm ) became rough, and there were some changes such as "cavitation" and "fissure formation" in the membrane. The intracellular ultrastructure was found to have obviously disrupted in the exposure groups, such as homogenization of cytoplasm, obvious change organelle structure, morphological damage of structure of nucleus, nuclear membrane disappearance, and chromatin pyknosis, and the changes were more obvious in Radi2 group. Compared with the sham group, the surface roughness (Ra) of cells in the exposure group was significantly intensified (P<0.05), and it was higher in Radi2 group than that in Radii group (P<0.05). Conclusion A 900MHz electromagnetic radiation may cause injury changes in NSCs membrane and ultrastructure in vitro, and the extent of injury may be related to the dosage of microwave irradiation.%目的 观察900MHz电磁辐射对体外培养大鼠海马神经干细胞超微结构的影响.方法 体外培养新生大鼠海马神经干细胞,分为假辐照组(0mw/cm2)、辐照1组(1mW/cm2)和辐照2组(3mW/cm2).假辐照组在辐照1组和2组进行辐照时置于常规条件下培养.辐照1组和辐照2组又根据辐照方式不同分为2个亚组:连续辐照亚组,于细胞接种后第2天起每天辐照2h,连续6d；一次性辐照亚组,于接种后第6天一次性辐照12h.采用原子力显微镜(AFM)观察细胞表面超微结构的变化,测定细胞膜表面的平均粗糙度,以轮廓算术平均偏差(Ra)表示.采用透射电镜(TEM)观察胞内超微结构的变化.结果 900MHz电磁辐射后,与假辐照组相比,辐照1组和2组神经干细胞表面粗糙,有“孔洞”、“裂隙”样改变,细胞质均匀化改变,细胞器结构明显改变,细胞核形态结构破坏,核膜消失,染色质固缩、边集,这些改变在辐照2组更为明显.与假辐照组相比,辐照1组和2组细胞表面粗糙度(Ra)明显增加(P＜0.05),其中辐照2组较辐照1组更为显著(P＜0.05).前述变化在连续辐照和一次性辐照的细胞中均存在且相似.结论 900MHz电磁辐射可致体外培养的神经干细胞胞膜和胞内超微结构出现明显的损伤样改变,且与微波辐照剂量可能有一定关系.