CIRCULARLY-POLARIZED, SINUSOIDAL, 50-HZ MAGNETIC-FIELD EXPOSURE DOES NOT INFLUENCE PLASMA TESTOSTERONE LEVELS OF RATS

We exposed rats to circularly polarized 50 Hz magnetic fields to deter mine if plasma testosterone concentration was affected. Previous exper iments indicate that magnetic fields suppress the nighttime rise in me latonin, suggesting that other neuroendocrine changes might occur as w ell. Male Wistar-King rats were exposed almost continuously for 6 week s to magnetic flux densities of 1, 5, or 50 mu T. Blood samples were o btained by decapitation at 12:00 h and 24:00 h. Plasma testosterone co ncentration showed a significant day-night difference, with a higher l evel at 12:00 h when studied in July and December, but the day-night d ifference disappeared when concentrations were studied in April. In th ree experiments, magnetic field exposure had no statistically signific ant effect on plasma testosterone levels compared with the sham-expose d groups. These findings indicate that 6 weeks of nearly continuous ex posure to circularly polarized, 50 Hz magnetic fields did not change p lasma testosterone concentration in rats. (C) 1994 Wiley-Liss, Inc.