This study evaluated the effects of chronic exposure to copper nanoparticles (Cu-NPs) and waterborne copper (CuSO₄) on the reproductive system of yellow catfish (Pelteobagrus fulvidraco). Juvenile yellow catfish were exposed to 100 and 200 μg Cu/L Cu-NPs and 100 μg Cu/L CuSO₄ for 42 days. The results showed clear reproductive defects in both female and male yellow catfish in the 200 μg Cu/L Cu-NPs and 100 μg Cu/L CuSO₄ groups. Exposure to Cu-NPs or CuSO₄ inhibited folliculogenesis and vitellogenesis in the ovaries, and spermatogenesis in the testes, accompanied by elevation of the apoptotic signal. Ultrastructural observations also revealed damaged organelles of gonadal cells in both testes and ovaries. Most of the hypothalamic-pituitary-gonadal (HPG) axis genes examined and serum sex steroid hormones tended to be downregulated after Cu exposure. Metabolomic analysis suggested that gonadal estradiol level is sensitive to Cu-NPs or CuSO₄. The heat map of gonadal metabolomics suggested a similar effect of 200 μg Cu/L Cu-NPs and 100 μg Cu/L CuSO4 in both the ovaries and testes. Additionally, metabolomics data showed that the reproductive toxicity due to Cu-NPs and CuSO₄ may occur via different metabolic pathways. Cu-NPs tend to dysregulate the metabolic pathways of sphingolipid and linoleic acid metabolism in the ovary and the biosynthesis of amino acids and pantothenate and CoA in the testis. Overall, these findings revealed the toxicological effects of Cu-NPs and CuSO₄ on the HPG axis and gonadal metabolism in yellow catfish.

_{本研究评估了长期接触铜纳米颗粒 (Cu-NPs) 和水性铜 (CuSO 4} ) 对黄颡鱼 ( Pelteobagrus fulvidraco ) 生殖系统的影响。将黄颡鱼幼鱼暴露于100和200μg Cu/L Cu-NPs和100μg Cu/L CuSO ₄中42天。结果表明，200 μg Cu/L Cu-NPs 组和 100 μg Cu/L CuSO ₄组雌性和雄性黄颡鱼均存在明显的生殖缺陷。暴露于 Cu-NP 或 CuSO ₄抑制卵巢中的卵泡发生和卵黄发生以及睾丸中的精子发生，并伴有细胞凋亡信号的升高。超微结构观察还揭示了睾丸和卵巢中性腺细胞的细胞器受损。大多数下丘脑-垂体-性腺 (HPG) 轴基因和血清性类固醇激素在铜暴露后往往会下调。代谢组学分析表明性腺雌二醇水平对 Cu-NPs 或 CuSO ₄敏感。性腺代谢组学热图表明 200 μg Cu/L Cu-NPs 和 100 μg Cu/L CuSO4 在卵巢和睾丸中具有类似的作用。此外，代谢组学数据表明 Cu-NP 和 CuSO _{4导致的生殖毒性}可能通过不同的代谢途径发生。Cu-NPs 往往会失调卵巢中鞘脂和亚油酸的代谢途径以及睾丸中氨基酸、泛酸和 CoA 的生物合成。_{总体而言，这些发现揭示了 Cu-NPs 和 CuSO 4}对黄颡鱼 HPG 轴和性腺代谢的毒理学影响。