Ganguly Satabdi, Adhikari Anupam, Sadhukhan Debalina, Raut Subhashree Subhasmita, Kumar V Santhana, Nag Subir Kumar, Das Basanta Kumar
ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata 700120, India.
ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata 700120, India.
Sci Total Environ. 2023 Nov 25;901:165958. doi: 10.1016/j.scitotenv.2023.165958. Epub 2023 Aug 2.
Cypermethrin (CYP) is a synthetic pyrethroid abundantly used in agriculture and aquaculture. It is an established potent endocrine disruptor to fish, yet the molecular mechanism behind its reproductive toxicity remains unclear. In this study, fish Labeo catla (Catla) was exposed to environmentally relevant concentration of CYP (0.7 μg/L) and 0.14 μg/L for 30 days. The changes in circulating sex steroids, genes, and hormones linked to the hypothalamic-pituitary-gonadal (HPG) axis, stress response and associated histological alterations were studied. Significant decline (P < 0.05) in serum 17 beta (β) estradiol (E2), 11 ketotestosterone (11-KT), and brain (FSH and GnRH) were observed in 0.7 μg/L dose of CYP. These effects may be due to the down-regulated expression of the upstream genes of the HPG axis i.e. Kiss 1 and Kiss 2, which further downregulates the expression of the GnRH gene. The decreased level of E2 and 11-KT also affects the vitellogenin (Vtg) gene expression, reducing the production of Vtg, a crucial protein for ovarian development. Principal component analysis (PCA) revealed the relationship between CYP and the biosynthesis of sex steroids. The toxic effect of CYP was also visible in antioxidant enzyme assay and related histological alterations. Overall, the study elucidated that long-term exposure to CYP, even at an environmentally relevant dose, may affect reproductive potential and fish recruitment. The study provides important insights into molecular mechanisms underlying CYP-induced endocrine disruption in fish, and it also raises questions about CYP's potential toxicity at environmentally relevant concentration in terms of understanding ecological risk.
氯氰菊酯（CYP）是一种广泛应用于农业和水产养殖的合成拟除虫菊酯。它是一种已确定的对鱼类有强效作用的内分泌干扰物，但其生殖毒性背后的分子机制仍不清楚。在本研究中，将印度鲮（Labeo catla）暴露于环境相关浓度的氯氰菊酯（0.7 μg/L）和0.14 μg/L 30天。研究了循环性类固醇、与下丘脑-垂体-性腺（HPG）轴相关的基因和激素的变化、应激反应以及相关的组织学改变。在0.7 μg/L剂量的氯氰菊酯处理组中，观察到血清17β雌二醇（E2）、11酮睾酮（11-KT）以及脑（促卵泡激素和促性腺激素释放激素）显著下降（P < 0.05）。这些影响可能是由于HPG轴上游基因即亲吻素1（Kiss 1）和亲吻素2（Kiss 2）的表达下调，这进一步下调了促性腺激素释放激素（GnRH）基因的表达。E2和11-KT水平的降低也影响卵黄蛋白原（Vtg）基因的表达，减少了Vtg的产生，Vtg是卵巢发育的关键蛋白质。主成分分析（PCA）揭示了氯氰菊酯与性类固醇生物合成之间的关系。氯氰菊酯的毒性作用在抗氧化酶测定和相关组织学改变中也可见。总体而言，该研究阐明，即使在环境相关剂量下长期暴露于氯氰菊酯也可能影响生殖潜力和鱼类补充。该研究为氯氰菊酯诱导鱼类内分泌干扰的分子机制提供了重要见解，同时也在理解生态风险方面提出了关于氯氰菊酯在环境相关浓度下潜在毒性的问题。
