Growth and apoptosis of Hep Gª²2 cells affected by extremely lowª²frequency electromagnetic field

    HUANG Xiaoª²Jun, YANG Jiaª²Ji, WANG Chunª²Mei, HUANG Xiaoª²Feng, LI Zhen, CAO

    Yunª²Xin, YU Hua, WANG Shuang, CHEN Dan

    1Electron Microscopic Center, 2Department of Immunology, Fourth Military Medical University, Xi¬ðan 710033, China

    ¡¾Abstract¡¿AIM: To investigate the effects of exposure to extremely lowª²frequency electromagnetic field (ELF) on the growth and apoptosis of Hep Gª²2 cells. METHODS: Hep Gª²2 cells were exposed to a 135Hz ELF for 6, 12, 24 h respectively and then the cellular viability, cell cycle and percentage of apoptotic cells in the treated Hep Gª²2 cells were measured respectively by methe thiazolyl tetrazolium (MTT) reduction assay and flow cytometry. The ultrastructural changes were observed by scanning and transmission electron microscopy. RESULTS: The absorbent value(A) was greatly decreased in Hep Gª²2 cells exposed to ELF, compared with that in the corresponding control groups (P<0.01). The cellular viability was remarkably decreased with the increasing of exposure time (P<0.01). The G1 stage of the Hep Gª²2 cells exposed to ELF was delayed and the percentage of apoptotic cells was increased with the increasing of exposure time. As shown by scanning and transmission electron microscopy, the treated cells were characterized by several specific morphologies: apoptotic cells shrank, formed blebs, while the plasma membrane and cellular organelles remained intact. In the nucleus, the chromatin condensed at the nuclear membrane. The cells disintegrated into apoptotic bodies. CONCLUSION: Exposure to 135Hz ELF can inhibit the viability of Hep Gª²2 cells and induce cell apoptosis. ......