为探讨胆汁酸对齐口裂腹鱼幼鱼生长、脂肪沉积、脂肪代谢及相关基因表达的影响；实验以360 尾初始体质量为( 12.74±0.14) g 的健康齐口裂腹鱼幼鱼为对象，随机分为4 组，每组设3个重复组，每个重复组放养30 尾，分别投喂胆汁酸含量为0、75、150 和300 mg/kg的4 种饲料，养殖时间为70 d。结果显示， 随着胆汁酸含量的升高，齐口裂腹鱼的增重率(WGR)呈先升高后降低的变化趋势，且在胆汁酸含量为150 mg/kg时达到最大，为226.63%；其肠脂肪酶(LPS)、肝酯酶(HL)、脂蛋白脂酶(LPL)和总脂酶(TL)活性均呈先升高后趋于稳定的变化趋势；而脂肪酸合成酶(FAS)活性则呈相反的变化趋势；齐口裂腹鱼肝脏LPL mRNA表达量呈先上调后趋于稳定的变化趋势，FAS mRNA表达量呈先下调后趋于稳定的变化趋势；肝脏、肌肉及全鱼中粗脂肪含量均随胆汁酸含量的升高呈先降低后趋于稳定的变化趋势，胆汁酸含量对实验鱼的成活率及脂肪沉积效率无显著性影响。研究表明，本实验条件下，添加适量的胆汁酸可有效上调齐口裂腹鱼LPL mRNA的表达量，下调FAS mRNA的表达量，增强脂肪代谢酶活性，促进对饲料脂肪的消化和利用，降低脂肪沉积，保护肝脏健康。
This experiment was conducted to investigate the effects of dietary bile acid levels on growth, lipid deposition，lipid metabolism enzyme activities and related gene expression of juvenile Schizothorax prenanti. A total of 360 juvenile S. prenanti with an average body weight of (12.74±0.14) g were randomly divided into 4 groups with 3 replicates per group and 30 fish per replicate.The diets with different bile acid supplemental levels (0，75，150 and 300 mg/kg) were fed to juvenile S. prenanti for 70 days. The results showed that: with bile acid supplemental level raising, the weight gain rate(WGR) had a trend of increasing first and decreasing later(P<0.05). The WGR was the highest (226.63%) when the bile acid supplemental level was 150 mg/kg. At the same time, the activities of intestinal lipase (LPS), hepatopancreas hepatic lipase (HL), lipoprotein lipase (LPL) and total lipase (TL) were all increased at first and then leveled off (P < 0.05), conversely, the activities of fatty acid synthase (FAS) were decreased at first and then leveled off (P < 0.05) with dietary bile acid levels raising. Meanwhile, with dietary bile acid levels raising, the liver LPL mRNA expression of S. prenanti increased first and then tended to stabilization (P<0.05), FAS mRNA expression decreased first and then tended to level off (P<0.05). The lipid content of liver, muscle and whole fish were all trended to level off with dietary bile acid levels raising (P < 0.05). As well as the survival rate and lipid deposition rate were not significantly different of S. prenanti (P > 0.05). Collectively, the results of above indicate that the suitable dietary bile acid levels can upregulate LPL mRNA expression and downregulate FAS mRNA expression of S. prenanti, enhance the activities of fat metabolism enzymes, promote the digestion and utilization of feed fat, reduce lipid deposition and protect liver health effectively.
XIANG Xiao, ZENG Benhe, WANG Rui, XU Yaosheng, ZHOU Xinghua, CHEN Jian, LI Daijin, ZHU Chengke, LIN Shimei. Effects of dietary bile acid on lipid deposition, lipid metabolism enzyme activities and related gene expression to juvenile Schizothorax prenanti[J]. Journal of Fisheries of China,2022,46(6):1045~1052复制