温度胁迫及恢复过程中褐牙鲆幼鱼GH、IGF-I、RNA／DNA比值和糖原的变化

褐牙鲆（Paralichthysolivaceus）幼鱼分别在温度8．5℃（T8.5）、13．0℃（T13.0）、17．5℃（T17.5）、22．0℃（T22.0）、26．5℃（T26.5）下养殖10d后，调整至生长最快的温度22．0℃养殖30d，研究了生长激素（GH）、类胰岛素生长因子I（IGF-I）、RNA／DNA比值和糖原质量分数的变化。除在胁迫阶段T17.5处理血浆IGF-I质量浓度显著低于T22.0处理外，不同处理的血浆GH和IGF-I质量浓度在胁迫和恢复阶段均无显著差异。不同处理的肝脏RNA／DNA比值仅在20-40d阶段有显著差异，不同处理的肌肉RNA／DNA比值在所有时间均无显著差异。胁迫结束时T8.5、T13.0、T26．5处理的肝脏糖原质量分数显著低于T17.5，处理，试验结束时T22.0处理肝糖原质量分数略低于其余处理。胁迫结束时T25.5处理肌肉糖原质量分数最高，而在恢复的第一个10d时T13.0处理肌肉糖原质量分数最高。不同温度下养殖10d导致的生长减缓能够在恢复至22．0℃后的30d内获得完全补偿生长，但此试验中GH、IGF-I和RNA／DNA比值与生长率不存在明显的相关性。

Changes of GH,IGF-I,RNA/DNA ratio and glycogen content of juvenile brown flounder during thermal stress and restoration

To investigate the changes of GH, IGF-I, RNA/DNA ratio and glycogen content of brown flounder （Paralichthys olivaceus） to thermal manipulation, we cultured the juveniles at 8.5 ℃（ T8.5 ） , 13.0℃（ T13. 0 ） , 17.5 22 （ T17.5 ） , 22. 0℃（ T22. 0 ） and 26.5 ℃ （T26.5） for 10 d, and then adjusted to 22. 0 22 for 30 d. The plasma IGF-I concentration of T17.5 was lower than that of T22.0 dining stress period, but no significant difference was found in plasma GH and IGF-I concentration at different temperatures during stress and restoration periods. RNA/DNA ratios were significantly different in liver during 20 ～40 d but not significantly different in muscle dur- ing the whole experimental period. The glycogen contents in liver of T8.5 , T13.0 and T26.5 were significantly lower than that of T17.5. At the end of the experiment, the glycogen contents in liver of T85, T13.0, T17.5 and T26.5 were slightly higher than that of T22.0. The gly- cogen contents in muscle of T26.5and T13.0were the highest at the end of stress period and on 20th day, repectively. The slow growth caused by 10-day culture at different temperatures could be completely compensated in 30 d after the temperature was adjusted to 22.0 ℃. No significant correlation was detected among plasma GH, IGF-I concentration, RNA/DNA ratio and growth rate.