Fuentes J, Eddy F B
Department of Biological Sciences, University of Dundee, Scotland, UK.
Comp Biochem Physiol A Physiol. 1997 Aug;117(4):487-91. doi: 10.1016/s0300-9629(96)00397-0.
Drinking rate in freshwater Atlantic salmon presmolts (about 0.1 ml/kg/h) was unaffected by daily injections of ovine GH (50 micrograms/fish) for a week but upon transfer to sea water an immediate and full drinking response was developed compared to saline treated fish (3.34 +/- 0.16 vs. 2.23 +/- 0.27 ml/kg/h). Smolting did not affect drinking rates in freshwater but after 7 days in sea water, salmon smolts imbibed 3.88 +/- 0.25 ml/ kg/h, significantly higher than the rate for saline injected presmolts (p < 0.05, one-way ANOVA), but not significantly different from oGH treated presmolts. Smolting and oGH treatment were without effect on plasma Na+ levels in freshwater fish and 7 days after transfer to sea water both groups showed a better regulation of plasma Na+ levels compared to saline treated presmolts. Atlantic salmon smolts showed higher levels of plasma Cl- than presmolts in freshwater, and after 7 days in sea water, both oGH presmolts and smolts showed significantly lower levels of plasma Cl- than saline injected presmolts. GH treatment in freshwater presmolts improved hypoosmoregulatory capacity following transfer to seawater and these results are discussed in relation to the physiology of smolting, and control of drinking.
淡水大西洋鲑幼鲑（约0.1毫升/千克/小时）的饮水速率在连续一周每天注射绵羊生长激素（50微克/鱼）后未受影响，但转移到海水中后，与盐水处理的鱼相比，出现了立即且完全的饮水反应（3.34±0.16对2.23±0.27毫升/千克/小时）。变态对淡水环境中的饮水速率没有影响，但在海水中7天后，鲑幼鱼的饮水量为3.88±0.25毫升/千克/小时，显著高于注射盐水的幼鲑（p<0.05，单因素方差分析），但与生长激素处理的幼鲑无显著差异。变态和生长激素处理对淡水鱼的血浆钠离子水平没有影响，转移到海水中7天后，与注射盐水的幼鲑相比，两组的血浆钠离子水平调节得更好。大西洋鲑幼鱼在淡水中的血浆氯离子水平高于幼鲑，在海水中7天后，生长激素处理的幼鲑和幼鱼的血浆氯离子水平均显著低于注射盐水的幼鲑。淡水幼鲑经生长激素处理后，转移到海水中的低渗调节能力得到改善，这些结果结合变态生理学和饮水控制进行了讨论。
