Endocrine Abstracts

Different studies have been done in the field of effect of magnetic field exposure on the biological organs. The aim of this study was to investigate the effects of static magnetic field (SMF) exposure on the secretion of hypothalamic-pituitary-gonadal axis in the male rats during short and long time exposed to SMFs (50 Hz).

Methods: Experiments have been done in four protocols. Each protocol included four groups (Wistar male rats, same range of age and weight) and each group contains 12 rats. After one-week adaptation they placed in exposure to SMF (0, 6, 12 and 24 mT) for 40 or 120 minutes daily for 17 or 34 days. All of protocols were started from 9:00 a.m. After experiments animals were anaesthetized, their blood has collected in separated tubes. Their serums were removed and kept frozen under -20  °C until use. Hormones were measured using gamma counter equipment with IRMA and RIA methods. The results were analyzed by ANOVA statistical method, followed by Tukey posthoc test (P<0.05).

Results: Subchronic exposures (40 min/day for 17 days) to SMFs have no effect on serum testosterone, LH and FSH levels. In contrast, SMFs (2 h/day for 17 days) induces a decrease of serum testosterone sham, vs. 6, 12 and 24 mT respectively (6.97±1, vs. 4.66±1.5; 2.6±0.59 and 2.8±0.64 ng/mL, P<0.05) and FSH levels (3.918±1, vs. 2.1±0.8; 0.765±0.037 and 0.715±0.01 mIU/mL, P<0.05).

Our results from third and forth protocols of experiments (40 min/day for 34 days) to 6 mT, SMF induces a increase of serum testosterone 6 mT vs sham, 12, and 24 mT respectively (7.53±2, vs. 1.84±0.6; 1.78±0.3 and 1.63±0.3 ng/mL, P<0.05) and 6 mT, SMF (2 h/day for 34 days) induces a increase of serum testosterone 6 mT vs 12 mT respectively (10.99±3, vs. 2.6±1; ng/mL, P<0.05).

Conclusions: Our results suggest that SMFs probably causes dysfunction in gonadal axis at the hypothalamic-pituitary level in male rats in different protocols. Subchronic exposure to short duration SMFs failed to alter hormonal levels in rat. In contrast, chronic exposure at low intensities increases testosterone.

Keywords: Magnetic fields; Rat; Testosterone; LH and FSH