Colleges of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, Shandong Province, China.
Colleges of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, Shandong Province, China.
Ecotoxicol Environ Saf. 2019 Mar;169:778-785. doi: 10.1016/j.ecoenv.2018.11.076. Epub 2018 Nov 29.
Metal pyrithiones (MePTs) are frequently used antifouling biocides in marine coatings. Their main degradation product, 2,2'-dithiobis-pyridine ((PS)), has been widely detected in seawater and may pose potential ecological risks. In the present study, sexually mature guppies (Poecilia reticulata) were exposed to (PS) at concentrations of 0, 20, 200, and 2000 ng/L for 28 days to investigate its reproductive toxicity. The results showed that (PS) significantly reduced testosterone (T) levels, spermatogenic cyst number and sperm motility, impeded spermatogenic cell differentiation in male guppies and delayed embryo development in females. These results indicated that (PS) could cause reproductive toxicity in guppies. We also examined mRNA expression of indices involved in the hypothalamic-pituitary-gonadal axis and reproductive behaviors. We found that 200 and 2000 ng/L (PS) decreased T synthesis by downregulating 17βHSD and CYP17 mRNA levels, and upregulating the mRNA level of CYP19a1a, which converted T to 17β-estradiol. (PS) also upregulated GnRH1, FSHβ, LHβ, and LHR mRNA levels, a positive feedback regulation due to the decrease of T levels in male guppies. Furthermore, (PS) significantly decreased CYP19a1b mRNA levels in all three exposure groups and thus reduced the display frequency of male guppies. This study was the first to report that (PS) could induce reproductive toxicity, which would provide a basis for future assessment of its ecological risk.
金属硫代吡啶（MePTs）是海洋涂料中常用的防污杀生剂。其主要降解产物 2,2'-二硫代双吡啶（（PS））已广泛检测到在海水中，可能构成潜在的生态风险。本研究采用性成熟的孔雀鱼（Poecilia reticulata）暴露于（PS）浓度为 0、20、200 和 2000ng/L 28 天，研究其生殖毒性。结果表明，（PS）显著降低了睾酮（T）水平、生精囊数量和精子活力，阻碍了雄性孔雀鱼的精母细胞分化，延迟了雌性胚胎发育。这些结果表明（PS）可引起孔雀鱼生殖毒性。我们还检查了参与下丘脑-垂体-性腺轴和生殖行为的指标的 mRNA 表达。我们发现 200 和 2000ng/L（PS）通过下调 17βHSD 和 CYP17 mRNA 水平，以及上调 CYP19a1a mRNA 水平来减少 T 的合成，后者将 T 转化为 17β-雌二醇。（PS）还上调了 GnRH1、FSHβ、LHβ 和 LHR mRNA 水平，这是雄性孔雀鱼 T 水平下降的正反馈调节。此外，（PS）在所有三个暴露组中显著降低了 CYP19a1b mRNA 水平，从而降低了雄性孔雀鱼的表现频率。本研究首次报道（PS）可诱导生殖毒性，这为其生态风险评估提供了依据。
