Feminizing endocrine disrupting compounds (EDCs) affect the growth and development of teleost fishes. The major regulator of growth performance, the growth hormone (Gh)/insulin-like growth-factor (Igf) system, is sensitive to estrogenic compounds and mediates certain physiological and potentially behavioral consequences of EDC exposure. Igf binding proteins (Igfbps) are key modulators of Igf activity, but their alteration by EDCs has not been examined. We investigated two life-stages (fry and smolts) of Atlantic salmon (Salmo salar), and characterized how the Gh/Igf/Igfbp system responded to waterborne 17α-ethinylestradiol (EE₂), 17β-estradiol (E₂) and 4-nonylphenol (NP). Fry exposed to EE₂ and NP for 21 days had increased hepatic vitellogenin (vtg) mRNA levels while hepatic estrogen receptor α (erα), gh receptor (ghr), igf1 and igf2 mRNA levels were decreased. NP-exposed fry had reduced body mass and total length compared to controls. EE₂ and NP reduced hepatic igfbp1b1, -2a, -2b1, -4, -5b2 and -6b1, and stimulated igfbp5a. In smolts, hepatic vtg mRNA levels were induced following 4-day exposures to all three EDCs, while erα only responded to EE₂ and E₂. EDC exposures did not affect body mass or fork length; however, EE₂ diminished plasma Gh and Igf1 levels in parallel with reductions in hepatic ghr and igf1. In smolts, EE₂ and E₂ diminished hepatic igfbp1b1, -4 and -6b1, and stimulated igfbp5a. There were no signs of compromised ionoregulation in smolts, as indicated by unchanged branchial ion pump/transporter mRNA levels. We conclude that hepatic igfbps respond (directly and/or indirectly) to environmental estrogens during two key life-stages of Atlantic salmon, and thus may modulate the growth and development of exposed individuals.

女性化的内分泌干扰化合物（EDC）影响硬骨鱼的生长和发育。生长激素（Gh）/胰岛素样生长因子（Igf）系统是生长性能的主要调节剂，对雌激素化合物敏感，并介导EDC暴露的某些生理和潜在行为后果。Igf结合蛋白（Igfbps）是Igf活性的关键调节剂，但尚未研究其通过EDC的改变。我们调查了大西洋鲑鱼（Salmo salar）的两个生命阶段（油炸和熏鲑），并描述了Gh / Igf / Igfbp系统如何响应水性17α-炔雌醇（EE ₂），17β-雌二醇（E ₂）和4-壬基酚（NP）。暴露于EE ₂和NP 21天的鱼苗肝脏增加卵黄蛋白原（vtg）mRNA水平降低，而肝雌激素受体α（erα），gh受体（ghr），igf1和igf2 mRNA水平降低。与对照组相比，暴露于NP的鱼苗具有减少的体重和总长度。EE ₂和NP降低肝igfbp1b1，-2a，-2b1，-4，-5b2和-6b1，并刺激igfbp5a。在软体动物中，暴露于所有三个EDC 4天后，诱导了肝脏vtg mRNA水平，而erα仅响应EE ₂和E ₂。EDC暴露不影响体重或前叉长度；然而，EE ₂降低了血浆Gh和Igf1的水平，同时降低了肝脏ghr和igf1的水平。在软体动物中，EE ₂和E ₂减少了肝igfbp1b1，-4和-6b1，并刺激了igfbp5a。如未改变的分支离子泵/转运蛋白mRNA水平所表明的，在鲑鱼中没有受损的离子调节的迹象。我们得出结论，肝igfbps 在大西洋鲑鱼的两个关键生命阶段中，它们（直接和/或间接地）对环境雌激素有反应，因此可能调节暴露个体的生长和发育。