【摘要】 目的探讨不同时间点锰暴露对大鼠睾丸睾酮、雌二醇、促卵泡激素和促黄体生成素的影响。方法选取健康成年雄性SD大鼠共96只,在本实验条件适应性喂养7 d后,根据预先设计的授时时间点(ZT2、ZT8、ZT14与ZT20)随机分为对照组与锰暴露组,每组12只。锰暴露组的剂量为30 mg/kg Mn Cl2,对照组为等容量的蒸馏水,采取腹腔注射的染毒方式,分别于各授时时间点进行染毒,每天1次,持续21 d。d22于相同的授时时间点处死动物,获取动物睾丸,检测其睾酮(T)、雌二醇(E2)、促卵泡激素(FSH)和促黄体生成素(LH)含量。结果锰暴露可引起睾丸激素的改变,但在不同的授时时间点,其睾丸T、E2、FSH、LH含量的改变不相一致。ZT2暴露时间点,FSH和LH降低,而T升高;ZT8暴露时间点,FSH降低,而E2和T升高;ZT14暴露时间点,所有观察指标变化差异无统计学意义;ZT20暴露时间点,FSH和LH降低,而E2和T升高。结论锰暴露所致的雄性生殖功能损伤具暴露时间差异性,在锰的生殖毒性评价时可能需考虑其暴露时间。更多还原

【Abstract】 Objective The aim of this study was to explore the chronotoxicity of the exposure of manganese(Mn) on reproductive hormones of testis in male rats. Methods Ninety-six healthy male SPF SD rats were accustomed in 12 h: 12 h light-dark photoperiod for one week and then were divided into four Mn-exposure groups and four control groups. Mn-exposure groups were intraperitoneally injected(i.p.) with Mn(30 mg/kg MnCl2·4 H2 O) and the control groups were administered with equal volume of water, respectively at zeitgeber time of ZT2, ZT8, ZT14 and ZT20 for continuous 21 days. The luteinizing hormone(LH), follicle-stimulating hormone(FSH), estradiol(E2) and testosterone(T) level of testis was measured by immunochemiluminometric assays(ICMAS) method and statistically analyzed by Cosinor analysis. Results Compared with the corresponding control groups, Mn-exposure groups showed change in the LH, FSH, E2 and T levels, but the results were different at different exposure time. At zeitgeber time of ZT2, the levels of FSH and LH decreased, and the level of T elevated. At zeitgeber time of ZT8, the level of FSH decreased, and the levels of T and E2 elevated. At zeitgeber time of ZT20, the levels of FSH and LH decreased, and the levels of T and E2 elevated. However, at zeitgeber time of ZT14, there was no significant change of our observation index. Conclusion The Mn-exposed male reproduction disorder had chronotoxicity.The exposure time may be considered when evaluating the male reproductive toxicity of manganese.更多还原