GH-IGF system regulation of attenuated muscle growth and lipolysis in Atlantic salmon reared at elevated sea temperatures
GH-IGF system regulation of attenuated muscle growth and lipolysis in Atlantic salmon reared at elevated sea temperatures
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DOI：
10.1007/s00360-012-0704-5
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发表时间：
2013-02-01
影响因子：
2
通讯作者：
Hansen, Tom
中科院分区：
文献类型：
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作者：
Hevroy, Ernst M.;Hunskar, Christine;Hansen, Tom
研究了大西洋鲑鱼（1.6 kg）在13、15、17和19℃海水中45天的生长调节，重点研究了生长激素（GH）、胰岛素样生长因子（IGF）和IGF结合蛋白（IGFBP）对饲料采食量、营养吸收、营养利用和内分泌的调节作用。在长时间的热暴露中，鲑鱼的采食量和生长减少。与低温条件下相比，在19℃条件下饲养45 d的鱼饲料利用率降低，体脂储存随着水温的升高而消耗殆尽。尽管血浆IGF-1浓度没有变化，但在17℃下饲养的鱼32-Da和43-kDa IGFBP升高，在19℃下饲养的鱼32-Da和43-kDa IGFBP下降，在15、17和19℃下饲养的鱼15和45 d时肌肉igf1 mRNA水平降低，在15 d后肌肉igf2 mRNA水平没有变化，但在45 d后降低。15和45 d后，肝脏igf2 mRNA水平随温度升高而降低，但温度对igf2 mRNA水平无影响。肝脏igfbp2b mRNA水平，对应于循环43-kDa IGFBP，在45天后表现出类似的反应。23 kDa的IGFBP仅在17℃饲养的鱼的血浆中检测到，相应的igfbp1b基因的上调表明存在时间依赖性的分解代谢反应，而在19℃饲养的鱼中没有观察到这一点。然而，在17和19℃饲养的鱼中检测到的肌肉ghr mRNA水平高于较低温度下的鱼，这表明肌肉中有脂溶调节。这些结果表明，大马哈鱼肌肉生长的减少是由igf1和igf2 mRNA水平的降低以及gh相关的脂溶作用介导的，以应对长时间的热暴露。因此，13摄氏度似乎是大西洋成年鲑鱼在海上生长的最佳温度。
Growth regulation in adult Atlantic salmon (1.6 kg) was investigated during 45 days in seawater at 13, 15, 17, and 19 A degrees C. We focused on feed intake, nutrient uptake, nutrient utilization, and endocrine regulation through growth hormone (GH), insulin-like growth factors (IGF), and IGF-binding proteins (IGFBP). During prolonged thermal exposure, salmon reduced feed intake and growth. Feed utilization was reduced at 19 A degrees C after 45 days compared with fish at lower temperatures, and body lipid storage was depleted with increasing water temperature. Although plasma IGF-1 concentrations did not change, 32-Da and 43-kDa IGFBP increased in fish reared at a parts per thousand currency sign17 A degrees C, and dropped in fish reared at 19 A degrees C. Muscle igf1 mRNA levels were reduced at 15 and 45 days in fish reared at 15, 17, and 19 A degrees C. Muscle igf2 mRNA levels did not change after 15 days in response to increasing temperature, but were reduced after 45 days. Although liver igf2 mRNA levels were reduced with increasing temperatures after 15 and 45 days, temperature had no effect on igf1 mRNA levels. The liver igfbp2b mRNA level, which corresponds to circulating 43-kDa IGFBP, exhibited similar responses after 45 days. IGFBP of 23 kDa was only detected in plasma in fish reared at 17 A degrees C, and up-regulation of the corresponding igfbp1b gene indicated a time-dependent catabolic response, which was not observed in fish reared at 19 A degrees C. However, higher muscle ghr mRNA levels were detected in fish at 17 and 19 A degrees C than in fish at lower temperatures, indicating lipolytic regulation in muscle. These results show that the reduction of muscle growth in large salmon is mediated by decreased igf1 and igf2 mRNA levels in addition to GH-associated lipolytic action to cope with prolonged thermal exposure. Accordingly, 13 A degrees C appears to be a more optimal temperature for the growth of adult Atlantic salmon at sea.