Low-dose-rate radiation exposure leads to testicular damage with decreases in DNMT1 and HDAC1 in the murine testis

This study examined the effects of continuous low-dose-rate radiation exposure (3.49 mgy/h) of gamma rays on mice testicles. c57bl/6 mice were divided into sham and radiation groups (n = 8 each),and were exposed to either sham irradiation or 2 gy for 21 days,0.2 gy for 2 days,or 0.02 gy for 6 h of low-dose-rate irradiation. testicular weight,seminiferous tubular diameter,and seminiferous epithelial depth were significantly decreased in the mice irradiated with 2 gy at 1 and 9 days after exposure. moreover,the low-dose-rate radiation exposure induced an increase in malondialdehyde levels,and a decrease in superoxide dismutase activity in the testis of mice irradiated with 2 gy at 1 and 9 days after exposure. the sperm count and motility in the epididymis also decreased in mice irradiated with 2 gy at 1 and 9 days after exposure,whereas there was no significant effect on the proportion of abnormal sperm. the expressions of dna methlytransferases-1 and histone deacetylases 1 in testes irradiated with 2 gy were significantly decreased compared with the sham group. in conclusion,the damage exerted on the testes and epididymis largely depended on the total dose of low-dose-rate radiation. © 2013 the author.