Influence of 50 Hz magnetic field on sex hormones and body, uterine, and ovarian weights of adult female rats

The effects of extremely low-frequency (ELF) magnetic fields on sex hormones of adult female Spague-Dawley rats were investigated. Adult female rats were exposed to a 50 Hz sinusoidal magnetic field at approximately 25 mu T (rms) for 18 weeks before they returned to their normal lift with unexposed counterparts. Serum level of Luteinizing Hormone (LH), Follicle Stimulating Hormone (FSH), progesterone, and estrogen were measured before, after, and during the exposure. Body and uterine weights were not affected by the field. A significant reduction in absolute and relative ovarian weights in exposed rats was observed when compared with sham-exposed controls (P < 0.05). The reduction in the levels of gonadotropins (FSH and LH) was significant after six weeks of exposure (P < 0.005). FSH levels were affected only on week 6 of exposure while LH remained affects were found at 6 and 12 weeks (P < 0.05). Interestingly, no significant effects were found at 6 and 12 weeks after removing the field. The level of progesterone and estrogen was significantly decreased after 12 weeks of exposure (P < 0.05), while no other of effects of progesterone level was observed during exposure or after removing the exposure. The level of estrogen was also significantly reduced at 12 weeks after removing the field (P < 0.05). These results suggest possible adverse effect on mammalian fertility and reproduction. The effects of ELF-MF on sex hormones were shown to be partly reversible.