Department of Biological Sciences, Evolutionary and Comparative Biology Section, University of Naples Federico II, Napoli, Italy.
Environ Toxicol. 2013 Oct;28(10):553-62. doi: 10.1002/tox.20749. Epub 2011 Aug 31.
The exposure to environmental toxicants such cadmium (Cd) is an important research area in wildlife protection. In this study, the effect of Cd oral administration on the ovarian structure and function and on reproductive performance of the Italian wall lizard Podarcis sicula was studied. In vivo, adult female lizards were randomly assigned to three groups. Cd was given with food in single dose and in multiple doses 3 days/week for 4 weeks at dose of 1.0 μg/g body weight. Following euthanasia, the ovaries were removed and analyzed for morpho-functional changes. Results demonstrated that Cd increases prefollicular germ cells number; the evaluation of the number of follicles detects significantly higher number of atretic growing follicles, whereas primary follicles remain unchanged with respect to controls. After Cd treatments, follicles are deformed by the presence of large protrusions and a general dysregulation in the follicle organization is observed. The zona pellucida is also affected. Cd causes alteration in sugar metabolism and in metallothionein gene expression. Finally, Cd administration significantly reduces clutch size and dramatically increases embryo mortality. In conclusion, data here described show that Cd induces morpho-functional alterations in lizard follicles and indicates that these are responsible for a significant impairment of oogenesis. The effects of the dose are time independent, persisting essentially unchanged regardless of single or multiple administration, so it can be concluded that even occasional, sublethal Cd contamination may significantly impair reproductive performance in these animals.
环境毒物如镉（Cd）的暴露是野生动物保护的一个重要研究领域。在这项研究中，研究了 Cd 口服给药对意大利壁蜥 Podarcis sicula 的卵巢结构和功能以及生殖性能的影响。在体内，成年雌性蜥蜴被随机分配到三组。Cd 通过食物单次和每周 3 天多次给药，剂量为 1.0μg/g 体重，持续 4 周。安乐死后，取出卵巢并分析形态功能变化。结果表明，Cd 增加了滤泡前生殖细胞的数量；对滤泡数量的评估发现，闭锁生长滤泡的数量显著增加，而与对照组相比，初级滤泡保持不变。在 Cd 处理后，滤泡被大的突起变形，并且滤泡组织的一般调节受到干扰。透明带也受到影响。Cd 导致糖代谢和金属硫蛋白基因表达的改变。最后，Cd 给药显著降低了产卵数，并显著增加了胚胎死亡率。总之，这里描述的数据表明，Cd 诱导了蜥蜴滤泡的形态和功能改变，并表明这些改变是卵母细胞发生的重要障碍。剂量的影响与时间无关，无论是单次或多次给药，基本上保持不变，因此可以得出结论，即使是偶尔的、亚致死剂量的 Cd 污染也可能显著损害这些动物的生殖性能。
