工频磁场抑制细胞缝隙连接通讯功能的剂量效应研究

A Study on Dose effect of Suppression to Gap Junctional Intercellular Communication Function By 50 Hz Magnetic Fields

目的研究５０Ｈｚ磁场对细胞缝隙连接通讯（ＧＪＩＣ）功能抑制作用的剂量效应关系及其有关机理。方法利用微注射法将荧光染料引入单个中国仓鼠肺来源成纤维（ＣＨＬ）细胞内，以５分钟后的荧光偶合细胞数作为ＧＪＩＣ功能的指标。研究了不同磁场强度、不同辐照时间对ＣＨＬ细胞ＧＪＩＣ的影响。结果工频磁场对ＧＪＩＣ的抑制作用与其强度有关，低强度（００５、０２和０４ｍＴ）的磁场辐照２４小时不能抑制ＧＪＩＣ，高强度（０８和１６ｍＴ）的磁场辐照２４小时能够抑制ＧＪＩＣ。在０～１６ｍＴ范围内，磁场对ＧＪＩＣ的抑制作用不呈“强度窗”效应。将强度固定为０８ｍＴ，５分钟的辐照无作用，１小时的辐照足以抑制ＧＪＩＣ，２４小时的辐照对ＧＪＩＣ的抑制作用最明显。此外，研究发现对ＧＪＩＣ的抑制主要是工频磁场本身的直接作用，而并非由磁场在被辐照物中受感应的电场所致。结论工频磁场对ＧＪＩＣ的抑制具有剂量效应关系。

Objective To study the relationship between dose of exposure to 50 Hz magnetic field (MF) and its effects of suppression to gap junctional intercellular communication (GJIC) function. Methods Lucifer yellow, a kind of fluorescent dye, was led into single CHL cell by iontophoretic injection. Number of dye coupled cells (DCC) five minutes after injection was used as an indicator for GJIC function. The effects of different intensities and irradiation of MF on GJIC in CHL cells were studied. Results Suppression to GJIC by 50 Hz MF depended on its flux intensity. Irradiation with lower flux intensity (0.05, 0.2 and 0.4 mT) of the MF for 24 hours could not inhibit GJIC, but that with higher intensity (0.8 and 1.6 mT) could. No “amplitude window” effect was appeared by irradiation with MF at intensities of zero to 1.6 mT. Exposure to MF at a fixed intensity of 0.8 mT for five minutes had no effects, but that for one hour was more than enough to inhibit GJIC, with the most apparent effects for 24 hour exposure. In addition, it was showed that suppression to GJIC was caused by direct action of 50 Hz MF rather then induced electrical field. Conclusion MF of 50 Hz had suppression to GJIC with a dose effect relationship.