Ornithine decarboxylase activity in L929 cells following exposure to 60 Hz magnetic fields.

To determine whether there is a biological basis for epidemiological studies which suggest an association between exposure to magnetic fields and cancer, we have attempted to replicate earlier findings on cellular enzymes related to cell proliferation. Here we report on an effort to replicate the doubling of ornithine decarboxylase (ODC) activity in L929 murine fibroblasts following exposure to 60 Hz magnetic fields reported by Litovitz et al. Efforts were made to reproduce the methods and exposure conditions used by the original investigators. Positive controls showed that our assay system responded to other known stimuli of ODC activity. We extended the previously reported investigations by testing a number of exposure conditions and other associated variables. Initial results suggested that cells exposed in the original investigators' laboratory demonstrated an enhanced enzyme activity, whereas cells exposed in our laboratory did not. Experiments in our laboratory using the most important elements of the original investigators' exposure system did not demonstrate any enhancement of ODC activity. Finally, a series of magnetic field exposure and sham exposure experiments conducted in the original investigators' laboratory failed to demonstrate an effect of magnetic fields on ODC activity.