因鱼类对糖的利用能力较低，水产养殖的鱼饲料使用大量昂贵的鱼粉（蛋白质）代替廉价的碳水化合物（糖类）为鱼类提供能量。胰岛素是鱼类调控糖代谢的重要激素。我们近期的研究显示在石斑鱼中尾加压素II (UII) 能显著抑制由葡萄糖诱导的胰岛素分泌。为系统探讨UII 对鱼类胰岛素的调控作用，我们将研究UII在石斑鱼脑、胰岛和肝脏三个糖代谢重要组织中对胰岛素合成与分泌的调控作用及相应的分子机理：1.通过检测因UII调控胰岛素而引起三种组织中糖代谢关键因子与酶基因表达及酶活变化来了解UII对鱼类糖代谢的影响；2.通过转录组和代谢组的关联分析来寻找UII对胰岛素的调控机制并进行验证；3.利用投喂实验探讨UII受体UT肽类拮抗剂Urantide在水产养殖中改善鱼类利用碳水化合物能力的应用潜力。本研究结果将为鱼类糖代谢基础理论增加新内容，为水产养殖通过改善鱼类对糖利用率，提高饲料中淀粉含量而降低成本提供新思路。

Since the ability of fish to use saccharine is low, in aquaculture, a large amount of expensive fishmeal (protein) has been used in place of cheap carbohydrates (saccharine) in feeds to provide energy to fish. Insulin is a very important hormone which regulates the glycometabolism of fish. Our previous study showed that urotensin II (UII) could significantly reduce the secretion of insulin evoked by glucose in grouper. To study systematically and thoroughly the regulation of UII on insulin, we'll investigate the regulation and its corresponding molecular mechanisms of UII on the synthesis and secretion of insulin in the brain, islet and liver, which are major sites for glycometabolism in fish：1. We’ll detect changes of mRNA expression of key factors and mRNA expression as well as enzyme activities of key enzymes related to fish glycometabolism. We’ll try to understand the influence of UII on fish glycometabolism via detecting those changes mentioned above which were induced by the regulation of UII on insulin. 2. to perform association analysis between transcriptome and metabolomics to find out the molecular mechanisms of UII regulation on insulin and confirm them via experiments. 3. to investigate the potential of urantide, a peptide antagonist of UT which is a specific receptor of UII, in improving the ability of fish to use carbohydrate in aquaculture via feeding experiments. Results in this study will provide new knowledge to fish glycometabolism. Moreover, it may provide a new idea in reducing the cost of feeds by means of the increase of starch content in feeds resulting from the improvement of the ability of fish to use saccharine in aquaculture.