Absence of ELF magnetic field effects on transcription of the connexin43 gene

Studies in our laboratory have revealed that extremely low-frequency (ELF) magnetic fields (MF) suppress gap junctional intercellular communication (G JIC) in cultured cells. To explore the molecular mechanisms, the effect of 50-Hz, 0.8-mT MF on connexin43 gene transcription was studied. Transcriptio nal levels of the connexin43 gene in the mouse fibroblast cell line NIH3T3 and Chinese hamster lung (CHL) cells were examined by Northern blot analysi s using a P-32-labeled connexin43 probe. Cells had been exposed to MF for 2 4 h and/or had received 2 h of 12-O-tetradecanoylphorbol-13-acetate (TPA) t reatment. The connexin43 gene transcriptional level did not change signific antly in any exposure groups.