CAJ | 학술논문

为研究网箱养殖密度对虹鳟甲状腺激素及血脂指标的影响，测定了血液中游离甲状腺激素 T3(FT3)、游离甲状腺激素 T4(FT4)、甘油三酯(TG)和总胆固醇(TC)含量，检测了高密度胁迫对肝脏和肠中 IGF-Ⅰ和肝脏、肾脏中 TR-α表达的影响。结果显示，随着养殖密度的升高 FT3和 FT4的含量逐渐降低，并且在11月份之前含量与养殖时间成正相关性；血清中TG含量随着密度的升高而降低， TC随着密度升高而升高，并且与温度存在负相关性，在11月份时密度处理组3(GR3)中的TG含量显著低于密度处理组1(GR1)，翌年1月份时3个密度处理组间都存在显著性差异(P<0.05)；而 IGF-Ⅰ和 TR-α也随着养殖密度的增加表达量逐渐降低。结果说明高密度网箱养殖作为一种环境胁迫因子使得血清中 FT3和 FT4含量降低，从而影响虹鳟鱼的生长发育，这一现象与特定生长率(SGR)的变化趋势一致。甲状腺激素含量的降低使得 TR-α表达量降低，实验中 IGF-Ⅰ的表达与甲状腺激素含量也存在相关性，甲状腺激素是否调控 IGF-Ⅰ的表达有待于进一步的研究。
위연구망상양식밀도대홍준갑상선격소급혈지지표적영향，측정료혈액중유리갑상선격소 T3(FT3)、유리갑상선격소 T4(FT4)、감유삼지(TG)화총담고순(TC)함량，검측료고밀도협박대간장화장중 IGF-Ⅰ화간장、신장중 TR-α표체적영향。결과현시，수착양식밀도적승고 FT3화 FT4적함량축점강저，병차재11월빈지전함량여양식시간성정상관성；혈청중TG함량수착밀도적승고이강저， TC수착밀도승고이승고，병차여온도존재부상관성，재11월빈시밀도처리조3(GR3)중적TG함량현저저우밀도처리조1(GR1)，익년1월빈시3개밀도처리조간도존재현저성차이(P<0.05)；이 IGF-Ⅰ화 TR-α야수착양식밀도적증가표체량축점강저。결과설명고밀도망상양식작위일충배경협박인자사득혈청중 FT3화 FT4함량강저，종이영향홍준어적생장발육，저일현상여특정생장솔(SGR)적변화추세일치。갑상선격소함량적강저사득 TR-α표체량강저，실험중 IGF-Ⅰ적표체여갑상선격소함량야존재상관성，갑상선격소시부조공 IGF-Ⅰ적표체유대우진일보적연구。
The aims of this study were to evaluate the effects of stocking density of Oncorhynchus mykiss that were reared in net cages on free triiodothyronine (FT3), free thyroxine (FT4), triglyceride (TG) and total cholesterin (TC) levels, and the expression of IGF-I and TR-α. The results showed that FT3 and FT4 levels decreased gradually as the stocking density increased, and they were positively associated with the culture time before November. TG levels de-creased as the stocking density increased while TC levels increased as the stocking density increased and both TG and TC levels were negatively associated with the culture temperature. Moreover, TG levels in the treatment group 3(GR3) were significantly lower than those in the treatment group 1(GR1) in November, and significant differences were ob-served among the three treatments in January of the following year (P < 0.05). Additionally, the expression levels of IGF-I and TR-αdecreased gradually as the stocking density increased. These results indicate that high stocking density could be a stressor for O. mykiss, that nd that may reduce FT3 and FT4 levels in the blood and then affect the growth and development of fish, which is supported by the trend of special growth rate (SGR). There was a relationship between thyroid hormone and the expression of IGF-I, The levels of thyroid hormone was related to the expression of IGF-I;however further investigation is needed to study whether thyroid hormone regulates the expression.