Down-regulation of metallothionein 1 and 2 after exposure to electromagnetic field in mouse testis.

BACKGROUND It is proved that testis is sensitive to electromagnetic field (EMF) and its damage results in infertility. Exposure to EMF induces reactive oxygen species production and affects on anti-oxidants defense mechanisms. Metallothionein (MT) is a name for a group of low molecular weight (6-7 kDa), sulfhydryl rich proteins. Expression of MT1 and MT2 genes in testis tissue after EMF exposure was aimed in this study. METHODS Male BALB/c mice (8 weeks old) were exposed to 3 MT EMF for 8 weeks, 4 hours/day. After 8 weeks, the mice were sacrificed and the testis tissue was removed. The testis pieces were stained with hematoxylin and eosin and analyzed under an optical microscope. Assessment of MT1 and MT2 genes and also protein expression was performed by real-time PCR and Western-blot, respectively. RESULTS In light microscopic observation, the number of primary spermatocytes was increased significantly in EMF group (P < 0.01). In addition, in interstitial space, the number of leydig cells was increased significantly in EMF group (P < 0.01) and basement membrane thickness was increased as well. MT1 and MT2 genes were down-regulated significantly in testis tissue of mice exposed to EMF both in mRNA and protein level compared to control. CONCLUSION It is clear that MT is mediated in testis development and spermatogenesis. Down-regulation of MT1 and MT2 after EMF in mouse testis might be followed by some consequences that result in infertility.