电磁脉冲暴露对幼龄雄性小鼠睾丸发育的影响

Effects of electromagnetic pulse exposure on development of testicle in the growing male mice

将96只3周龄雄性BALB/c小鼠按体质量随机分为假暴露组和暴露组。暴露组小鼠每日接受场强200kV/m、脉冲数400次电磁脉冲(Electromagnetic pulse,EMP)暴露,连续暴露30 d,2 h/d,暴露期间观测小鼠体质量的变化。于照后第1、7、14、21、30和60天检测暴露后小鼠睾丸指数、精子数量、精子畸形率、精子凋亡及睾丸组织中肿瘤转移相关基因-1(Metastasis tumor antigen 1,MTA-1)蛋白和信使核糖核酸(m RNA)表达量。结果表明:与假暴露组相比,暴露组小鼠体质量从照射第8天至第28天明显降低;睾丸指数于照后第21天至第60天明显降低;精子数量于照后第7天至第60天明显减少;精子畸形率从照后第1天至第30天时增高;生精细胞凋亡率在照后第1天和第60天时明显增高,但在照后第7天和第14天时明显降低;睾丸组织中MTA-1蛋白表达量于照后第1、7、14和60天时明显降低,且MTA-1mRNA表达量也于照射后第1天至第21天时明显降低。结果提示一定参数的EMP暴露可能通过影响MTA-1表达水平而对幼龄雄性BALB/c小鼠睾丸发育造成损伤。

Ninety-six mice aged 3 weeks were randomly divided into two groups： a group exposed to electromagnetic pulse（EMP） at 200 k V/m in 400 pulses for 30 d, 2 h/d, and a sham-exposure group. The body weights were measured during the exposure time. The testicular index; sperm count, sperm deformity rate, spermatogenic cells apoptosis; and metastasis tumor antigen 1（MTA-1） protein and m RNA expression in testicles were measured at 1-, 7-, 14-, 21-, 30-, and 60-day time points after exposure. The results showed that body weights in the exposure group were significantly lower than those in the sham-exposure group on days 8～28 of EMP exposure（p〈0.05）; compared with that in the sham-exposure group, testicular index in the exposure group decreased significantly on days 21～60 after exposure; sperm count decreased on days 7～60 after exposure; the rate of sperm deformation increased on days 1～30 after exposure; apoptotic spermatogenic cells increased on days 1 and 60 but decreased on days 7 and 14 after exposure（p〈0.05）; MTA-1 protein expression in testicles decreased significantly at all time points after exposure; and m RNA expression decreased on days 1～21 after exposure. The reduced testicular indexes and sperm quality, as measured by the decreases in MTA-1 protein and m RNA, suggest that EMP exposure inhibits the development of testicles in growing male mice.