INHIBITION OF MELATONIN IN THE PLASMA OF 3RD-GENERATION MALE-MICE UNDER THE ACTION OF ELF MAGNETIC-FIELDS

The pineal gland has been considered a magnetic receptor organ that re gulates circadian rhythms by means of the secretion of melatonin, a po tent oncostatic agent that prevents the initiation and promotion of ca ncer. ELF electromagnetic radiation, similar to that generated by powe r lines, can alter melatonin plasma levels. To study this effect, 4 OF 1 mice generations have been reared subjected to a lifelong 15 mu T, 5 0 Hz magnetic field action. This magnetic field was generated inside a Helmholtz coil system. The concentration of melatonin in the blood ha s been determined on 40 male mice of the third generation by means of RIA, as they reached sexual maturity (3 months). A radical decrease, m ore remarkable at night, of the melatonin plasma levels and the loss o f the night-day secretion rhythm was observed in the experimental grou p. These results could be the consequence of the applied magnetic fiel d cumulative effect. The secretion rhythms of other hormones, at the l evel of the hypothalamic-hypophyseal axis, might be altered as an effe ct of those results. This chronobiological change could explain the di fferent findings in the 4 generations of mice subjected to the same ex perimental model.