Improving carbohydrate utilization can contribute to sustainability of aquaculture. In order to explore the feedback mechanism of glucose homeostasis in fish, one control diet (25% carbohydrate and 40% protein), one relatively high carbohydrate diet named HG (42% carbohydrate and 40% protein), and one high dietary carbohydrate coupled with relatively low protein diet named HGP (42% carbohydrate and 25% protein) were fed to grass carp for 40 days. After the feeding trial, HG group impeded the food intake and growth performance of fish compared with the other two groups. Meanwhile, the serum glucose and insulin level were both significantly elevated under the condition of high carbohydrates intake when compared HG with control group. However, although no significant difference was observed in peripheral glucose or insulin between HG and HGP groups, fish fed with HGP diet increased growth performance and food intake compared with the HG group. Gene expression data indicated that fish selectively regulated the expressions of the cerebral anorexigenic genes (cart and pomc) to adapt to the HG and HGP intake. Therefore, the HGP diet with high carbohydrate and low protein was more suitable for grass carp feeding and growth when compared with the other two diets, possibly because the diet composition was closer to the natural food of this fish. In addition, the serum leptin level was highly consistent with changes in food intake and anorexigenic gene expressions when comparing the three experimental diets, indicating that leptin might be the key to mediate the feedback regulation of carbohydrates intake on food intake and appetite in fish.

提高碳水化合物的利用有助于水产养殖的可持续性。为了探索鱼体内葡萄糖稳态的反馈机制，一种对照饮食（25% 碳水化合物和 40% 蛋白质），一种相对高碳水化合物的饮食称为 HG（42% 碳水化合物和 40% 蛋白质），以及一种高碳水化合物饮食加上将相对低蛋白质的饮食称为 HGP（42% 碳水化合物和 25% 蛋白质）喂给草鱼 40 天。投喂试验后，与其他两组相比，HG组阻碍了鱼的摄食和生长性能。同时，与对照组相比，在高碳水化合物摄入条件下，血糖和胰岛素水平均显着升高。然而，虽然在 HG 和 HGP 组之间未观察到外周葡萄糖或胰岛素的显着差异，与 HG 组相比，喂食 HGP 饮食的鱼增加了生长性能和食物摄入量。基因表达数据表明，鱼类选择性地调节脑厌食基因的表达。cart和pomc ) 以适应 HG 和 HGP 的摄入量。因此，与其他两种日粮相比，高碳水化合物低蛋白的HGP日粮更适合草鱼的摄食和生长，可能是因为日粮成分更接近这种鱼的天然食物。此外，比较三种实验日粮时，血清瘦素水平与摄食量和厌食基因表达的变化高度一致，表明瘦素可能是介导碳水化合物摄入对鱼类摄食量和食欲的反馈调节的关键。