Changes in Mouse Adrenal Gland Functionality Under Second-Generation Chronic Exposure to Elf Magnetic Fields. I. Males

The second generation of male OF1 mice chronically exposed to a magnetic field of 50 Hz and 15 mu T were studied to elucidate the possible histological and endocrinological alterations in adrenal gland caused by this exposure. Animals were sacrificed at the age of 10 weeks. Cortisol plasma concentrations were determined by fluorescence polarization immunoassay, and adrenal glands were studied by histopathological methods. The body weight of the exposed animals was found to be significantly increased. Cortisol plasma concentration and adrenal cortex thickness lost the daily rhythmicity. The statistical histopathological study showed no differences in exposed versus control animals. However, 15-20% of the experimental mice present nodular cortical hyperplasia with hypertrophy, increase in dark cells, and islets of cells with large lipid vacuoles. At the ultrastructural level, a dramatic decrease in lipid content and increase in mitochondria and SER compartment and in the nuclear and nucleolar volumes were found in every cortical zone of the exposed animals compared with controls, as well as a large vasodilation in the zone reticularis. No differences in the medulla of control and experimental groups could be appreciated.