Condensed tannins (CT) have been observed to be beneficial to maintain glucose homeostasis and improve carbohydrate utilization for livestock, whereas little information is available about the effects of CT on glycometabolism of fish. Three diets were formulated to contain approximately 15 % carbohydrate (G1), 39 % carbohydrate (G2), and G2 supplemented with 0.1 % CT. A total of 225 juvenile were randomly assigned to 3 groups (triplicate tanks per group) with 25 fish in each tank and fed to apparent satiation during 56-d feeding trial. Results indicated that fish fed G2 had lower (p < 0.05) final body weight, weight gain rate, feed intake, specific growth rate and serum insulin concentration, but higher (p < 0.05) feed efficiency ratio and serum glucose, total antioxidant capacity, superoxide dismutase, immunoglobulin M and lipopolysaccharide than those fish fed G1 or G3. The activity of pyruvate kinase (PK) was lower (p < 0.05) but glucokinase (GK) was higher (p < 0.05) in G2 than in G1 or G3. Gene expression of insulin like growth factor Ⅰ and PK were down-regulated (p < 0.05), whereas GK was up-regulated (p < 0.05) in G2 than in G1 or G3. No difference (p> 0.05) in these gene expressions were observed between G1 and G3. It was concluded that fed diet with 39 % carbohydrate exhibited depressed growth performance, increased antioxidant and immune capacity, and hyperglycemia. Supplementation of 0.1 % CT resulted in improved growth performance and decreased serum glucose concentration, mainly due to the positive effects of CT on the activity and gene expression of hepatic glycolysis and gluconeogenesis enzymes of .

中文翻译：

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高水平碳水化合物和补充缩合单宁对花鲈生长性能、血清代谢物、抗氧化和免疫反应以及肝脏糖代谢基因表达的影响


据观察，缩合单宁 (CT) 有利于维持葡萄糖稳态并提高牲畜碳水化合物的利用率，但有关 CT 对鱼类糖代谢影响的信息很少。三种饮食配制为含有约 15% 碳水化合物 (G1)、39% 碳水化合物 (G2) 和补充有 0.1% CT 的 G2。总共 225 只幼鱼被随机分配到 3 组（每组有 3 个池），每个池中 25 条鱼，并在 56 天的喂养试验中喂至明显饱食。结果表明，饲喂 G2 的鱼的最终体重、增重率、采食量、特定生长率和血清胰岛素浓度较低（p < 0.05），但饲料效率比和血清葡萄糖、总抗氧化能力较高（p < 0.05）。超氧化物歧化酶、免疫球蛋白M和脂多糖均高于饲喂G1或G3的鱼。 G2 中的丙酮酸激酶 (PK) 活性低于 G1 或 G3 (p < 0.05)，但葡萄糖激酶 (GK) 活性较高 (p < 0.05)。与 G1 或 G3 相比，G2 中胰岛素样生长因子 Ⅰ 和 PK 的基因表达下调（p < 0.05），而 GK 的基因表达上调（p < 0.05）。 G1 和 G3 之间这些基因表达没有观察到差异 (p> 0.05)。结论是，饲喂含有 39% 碳水化合物的饮食表现出生长性能下降、抗氧化和免疫能力增强以及高血糖。补充0.1%CT可改善生长性能并降低血清葡萄糖浓度，这主要是由于CT对肝糖酵解和糖异生酶的活性和基因表达的积极影响。