Department of General Biology, Federal University of Viçosa (UFV), Av. P.H. Rolfs, s/n, Campus Universitário, Viçosa, Minas Gerais, Brazil.
Biol Trace Elem Res. 2018 Jun;183(2):314-324. doi: 10.1007/s12011-017-1139-3. Epub 2017 Sep 8.
Aluminum (Al) is the most widely distributed metal in the environment and is extensively used in human daily life without any known biological function. It is known that exposure to high concentrations of Al impacts negatively on serum testosterone levels, testicular histomorphometry, and sperm parameters; however, no information is available about the effects of low exposure levels on reproduction. International organizations have established the Al concentration tolerated in drinking water as 3.35 × 10 mg/kg. Therefore, we aimed to compare the effects of long-term exposure to low and high concentrations of Al on male reproductive functions, focusing on testis, epididymis, and sperm parameters. Adult Wistar rats were exposed to aluminum chloride (AlCl) at 6.7 × 10, 3.35 × 10, 10, and 40 mg/kg for 112 days by gavage. Al-exposed animals presented low values of testis and epididymis weight, and serum testosterone levels when compared to controls. The stereology of Leydig cells, epididymis histomorphometry, sperm motility, and structural integrity of sperm membranes changed depending on the Al concentration. In regard to epididymis histomorphometry, the initial segment and caput regions were more affected by Al exposure than distal regions. Otherwise, the histology of testis and epididymis did not alter after the Al exposure, as well as sperm morphology. In summary, we concluded that the consequences of Al exposure at low levels were as negative as high levels on reproductive parameters, suggesting adverse impact on male fertility.
铝（Al）是环境中分布最广泛的金属，广泛应用于人类日常生活中，但其没有任何已知的生物学功能。已知暴露于高浓度的铝会对血清睾酮水平、睾丸组织形态计量和精子参数产生负面影响；然而，目前尚无关于低暴露水平对生殖影响的信息。国际组织已将饮用水中可耐受的铝浓度设定为 3.35×10mg/kg。因此，我们旨在比较长期暴露于低浓度和高浓度铝对雄性生殖功能的影响，重点关注睾丸、附睾和精子参数。成年 Wistar 大鼠通过灌胃暴露于氯化铝（AlCl）的浓度分别为 6.7×10、3.35×10、10 和 40mg/kg，共 112 天。与对照组相比，铝暴露动物的睾丸和附睾重量以及血清睾酮水平较低。睾丸间质细胞的立体学、附睾组织形态计量、精子运动和精子膜结构完整性发生变化，这取决于铝浓度。就附睾组织形态计量而言，与远端区域相比，初始段和头部区域更容易受到铝暴露的影响。然而，暴露于铝后，睾丸和附睾的组织学以及精子形态没有改变。总之，我们得出结论，低水平铝暴露的后果与高水平暴露一样对生殖参数产生负面影响，表明对男性生育力有不利影响。
