Effects of subchronic exposure to static magnetic field on testicular function in rats

Background. The aim of this study was to investigate the effect of static magnetic field (SMF) exposure on testicular function, antioxidant status and DNA oxidation in rats. Methods. Male adult rats were exposed to SMF (128 mT; 1 h/day for 30 days). After sacrifice, the epididymal sperm number was counted. Testosterone concentration in plasma and testis was measured by radioimmunoassay. MDA level and GPx, CAT and SOD activities were used as markers of oxidative stress in testis. The 8-oxo-dG level is measured by the HPLC-EC system. Results. Subchronic exposure to SMF has no effect on epididymal sperm count, spermatozoa motility and genital organ weight. In contrast, SMF induces a decrease of testicular and plasmatic testosterone levels, respectively (1.48 +/- 0.56 vs. 4.66 +/- 0.51 ng/g, p < 0.05; 0.97 +/- 0.16 vs. 1.64 +/- 0.18 ng/mL, p < 0.05). Exposed rats displayed an increase of malondialdehyde (2.01 +/- 0.03 vs. 1.47 +/- 0.06 mu mol/g protein, p < 0.05), metallothioneins (1.04 +/- 0.22 vs. 0.37 +/- 0.06 mu g/g, p < 0.05) and 8-oxo-dG concentrations (3.38 +/- 0.30 vs. 2.36 +/- 0.28 8-oxo-dG/10(6) bases, p < 0.05) in the testis. In the gonad, SMF decreases the CAT (14.33 +/- 1.16 vs. 21.67 +/- 2.05 U/mg protein, p < 0.05), GPx (177.40 +/- 5.97 vs. 237.20 +/- 15.65 U/mg protein, p < 0.05) and mitochondrial Mn-SOD (2.95 +/- 0.10 vs. 3.53 +/- 0.29 U/mg protein, p < 0.05) activities. However, cytosolic CuZn-SOD activity is unaffected. Conclusions. Subchronic exposure to SMF failed to alter spermatogenesis in rat testis. In contrast, the same treatment decreased testosterone levels and induced DNA oxidation. (C) 2006 IMSS. Published by Elsevier Inc.