Faculty of Chemistry and Environmental Science, Guangdong Ocean University, Zhanjiang 524088, China.
Faculty of Chemistry and Environmental Science, Guangdong Ocean University, Zhanjiang 524088, China; Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, South China Normal University, Guangzhou 510006, China.
Aquat Toxicol. 2024 Nov;276:107105. doi: 10.1016/j.aquatox.2024.107105. Epub 2024 Sep 19.
Progestins are crucial steroid hormones that have attracted wide attention due to their endocrine disrupting effects in fish. The aim of this study is to investigate the effects of long-term exposure to low concentrations of norgestrel (NGT) on the reproductive and thyroid endocrine systems of adult zebrafish. Adult zebrafish were exposed to 7 and 39 ng/L NGT for a duration of 90 days. The results revealed that exposure to 39 ng/L NGT led to a significant up-regulation of 3β-hydroxysteroid dehydrogenase (hsd3b) and 20β-hydroxysteroid dehydrogenase (hsd20b) genes in the ovary of female zebrafish. Additionally, there was a significant up-regulation of 11β-hydroxysteroid dehydrogenase 2 (hsd11b2) gene in the testis of male zebrafish. Furthermore, egg production decreased significantly, accompanied by notable alterations in the proportion of ovarian development stages, as well as reductions of sex hormone levels (E2, 11-KT, and T) in both females and males. However, long-term exposure to low concentrations of NGT did not lead to changes in thyroid hormone levels and thyroid histopathology in adult zebrafish. The overall results imply that environmental concentrations of NGT have a strong endocrine disrupting effect on the reproductive system of zebrafish, while the thyroid system is not sensitive to NGT exposure. The present study underscores the reproductive endocrine impacts of NGT and emphasizes the necessity for prolonged exposure at environmental concentrations.
孕激素是重要的甾体激素，由于其对鱼类的内分泌干扰作用而受到广泛关注。本研究旨在探讨长期低浓度去甲孕烯酮（NGT）暴露对成年斑马鱼生殖和甲状腺内分泌系统的影响。成年斑马鱼分别暴露于 7 和 39ng/L 的 NGT 中 90 天。结果表明，39ng/L 的 NGT 暴露导致雌性斑马鱼卵巢中 3β-羟甾脱氢酶（hsd3b）和 20β-羟甾脱氢酶（hsd20b）基因显著上调。此外，雄性斑马鱼睾丸中 11β-羟甾脱氢酶 2（hsd11b2）基因也显著上调。同时，产卵量显著下降，伴随着卵巢发育阶段比例的明显改变，以及雌雄鱼的性激素水平（E2、11-KT 和 T）降低。然而，长期低浓度 NGT 暴露不会导致成年斑马鱼甲状腺激素水平和甲状腺组织病理学发生变化。总的来说，结果表明环境浓度的 NGT 对斑马鱼的生殖系统具有很强的内分泌干扰作用，而甲状腺系统对 NGT 暴露不敏感。本研究强调了 NGT 的生殖内分泌影响，并强调了在环境浓度下进行长期暴露的必要性。
