Study On The Effects Of 50 Hz Magnetic Fields On GAP Junctional Intercellular Communction, Its Related Factors And Mechanism

In bioelectromagnetics concern is rising on that if 50 Hz electromagnetic fields affect health, particularly 50 Hz magnetic fields (MFs) influence cancer development. On the bases of these studies at the level of epidemiology, intact animal, and molecule, some scientists pointed out that MFs might act as tumor promoter rather than initiator. However, the results are not constant, and the mechanism of MFs on cancer promotion and related factors are unknown, and therefore much conversy has been evoked at home and abroad.Cancer promotion might be a process resulting from an uncontroled growth of mutated cells. Growth of normal cells are dependent, to some extent on their ability to recognize cells, and perhaps on communication with neighboring cells. Gap junctional intercellular communication (GJIC) is one of important communication among cells in living system, and plays an essential role in regulation of cell growth and differentiation. Based on many studies related to the suppression of GJIC and cancer promotion, we reasonably believe that suppression of GJIC is key step in cancer promotion.In the present experiment, we used GJIC function as index to explore if 50 Hz MFs can act as cancer promoter or co-promoter, and to explore its related factors (e.g. magnetic flux density, exposure duration, waveform, and induced electric field), and the mechanism of GJIC inhibition induced by MFs. 1) The effects of 50 Hz magnetic fields on GJIC and related factorsWe designed and established two sets of exposure systems (one is sinusoidal MFs and another 1:9 pulse MFs), generating very uniform MFs in the central area (10cm×10 l×cm× 10cm) for cell exposure within a CO₂ incubator in which the magnetic flux densities could be regulated from 0 to 1.6 mT, and from 0 to 0.8 mT respectively. The magnetic flux densities were determined with a Model- 120 meter made in U.S.A. CHL or NIH/3T3 cells were routinely incubated in tissue culture dishes. When the cells just reached near confluence in the dishes for four days, the dishes were placed in the central area of the...