工频磁场对星形胶质细胞间隙连接通讯功能的影响

Effects of power frequency magnetic field on gap junction intercellular communication of astrocytes

目的 探讨工频磁场 (PFMF)是否有促癌或协同促癌作用。方法 利用荧光光漂白后再恢复法观察漂白细胞荧光强度的恢复以判断经间隙连接的细胞间通讯 ,以相对荧光强度恢复速率(CFIRR)作为对细胞间隙连接通讯 (GJIC)作用的评价指标 ,研究不同磁场强度单独作用或协同佛波酯(TPA)对星形胶质细胞GJIC功能的影响。结果 3ng/mlTPA作用 1h时CFIRR的中位数 (Md)值为4 .53 % /min ,空白对照组为 9.74% /min ,两组的差异有显著性 (H =1 2 .0 84,P <0 .0 0 5)。 0 .8或 1 .6mT磁场作用 2 4h时CFIRR的Md 分别 8.2 5、6 .68% /min ,与空白对照组比较 ,差异无显著性 (H =32 .61 7,P >0 .0 5)。 0 .8或 1 .6mT磁场作用 2 3h ,再与TPA共同作用 1h时CFIRR的Md 分别为 3 .32、2 .85% /min ,与TPA组比较 ,差异无显著性 (H =2 .589,P >0 .0 5)。结论 0～ 1 .6mT的 50Hz磁场单独作用不能抑制星形胶质细胞GJIC功能 ;协同TPA ,不能增强TPA对星形胶质细胞GJIC的抑制作用 ;

Objective In order to explore if power frequency magnetic field(PFMF) can act as cancer promoter or be synergistic with phorbol 12 myristate 13 acetate(TPA) in cancer promotion,the effects of 50 Hz MF on gap junction intercellular communication(GJIC) of astrocytes were observed. Methods Fluorescence redistribution after photobleaching(FRAP) was adopted to observe the recovery of fluorescence intensity in the bleached cells thus to estimate intercellular communication by gap junction.Comparative fluorescence intensity recovery rate(CFIRR)was as evaluation index.The effects of 50 Hz MF alone or with TPA on GJIC of astrocytes were studied. Results After 3 ng/ml TPA treatment for 1 hour, M d of CFIRR was 4.53 %/min,whereas that in the control group was 9.74 %/min( H = 12.084, P <0.005).After exposure to 0.8 and 1.6 mT magnetic field for 24 hours respectively, M d of CFIRR was 8.25 %/min and 6.68 %/min respectively,no significant difference from that of control ( H =32.617, P >0.05).After exposure to 0.8 and 1.6 mT magnetic field for 23 hours then combined with 3 ng/ml TPA treatment for 1 hour, M d of CFIRR was 3.32 %/min and 2.85 %/min respectively,also no significant difference from that in the group treated with 3 ng/ml TPA alone( H =2.589, P >0.05). Conclusion 50 Hz MF(within 0～1.6 mT) alone could not inhibit GJIC of astrocytes;with TPA,could not enhance the inhibition of TPA on GJIC of astrocytes.But with MF intensity increasing,the inhibition of MF on GJIC showed elevated tendency.