Hormonal Control of Lipid Metabolism in Fish

9305554谢里丹最近的研究表明，存在多种形式的生长抑素，这是一种最初从大脑中分离出来的多肽，被发现含有14个氨基酸(来自基因I)，并能抑制生长激素的分泌，但后来发现它位于许多脊椎动物的胰腺、胃肠道和其他地方。生长抑素的多种形式(14-氨基酸形式和N-末端延伸形式)的特殊意义以及这些因素在调节脂质代谢中的作用尚未确定。通过这项拟议的工作，谢里登博士试图评估生长抑素在鱼类脂肪代谢协调中的作用。鱼类为研究这些问题提供了一个独特的系统，因为它们的进化地位，多样化的脂肪储存策略(将脂肪储备分配到几个储存库：肠系膜脂肪、肝脏和暗肌肉)，以及分离的内分泌胰腺(Brockman体)，具有丰富的N-末端延伸的生长抑素(生长抑素-25；来自基因II)。他将首次展示基因I和基因II生长抑素对脂肪代谢的不同影响。这项分析将展示各种胰腺激素(如生长抑素、胰岛素、胰升糖素、胰多肽)之间的重要相互作用，并评估生长抑素对肝脏脂肪分解的直接影响，包括细胞作用模式。他还将首次评估生长抑素与肝脏的结合，生长抑素是鱼类的主要脂肪储存库，并检查生长抑素结合特性(亲和力、容量)在营养(葡萄糖)和激素(INS，GLU)处理后的变化。虽然这项研究专门针对鱼类，但这项研究将提供有关生长抑素生理的一般新信息。这些结果将有助于基本了解激素对肝脏脂代谢的调控，并为脂代谢调控方案的演变提供重要的洞察力。***

9305554 Sheridan Recent studies have indicated the existence of multiple forms of somatostatin, a peptide originally isolated from the brain and found to contain 14-amino acid (from gene I) and to inhibit growth hormone secretion, but subsequently found to be located in the pancreas, gastrointestinal tract and elsewhere of many vertebrates. The special significance of multiple forms (14-amino acid forms and N-terminally extended forms) of somatostatins, and the roles of these factors in regulation of lipid metabolism, have yet to be determined. With the proposed work, Dr. Sheridan seeks to evaluate the role of somatostatins in the coordination of lipid metabolism in fish. Fish offer a unique system for the study of these questions because of their evolutionary position, diversified lipid storage strategy (partitioning of lipid reserves among several depots: mesenteric fat, liver and dark muscle), and segregated endocrine pancreas (Brockman body) possessing abundant amounts of N-terminally extended somatostatin (somatostatin-25; from gene II). He will demonstrate for the first time the differential effects of gene I and gene II somatostatins on lipid metabolism. This analysis will demonstrate important interactions among the various pancreatic hormones (e.g., somatostatins, insulin, glucagon, pancreatic polypeptide) and evaluate the direct effects, including cellular mode of action, of somatostatins on hepatic lipolysis. He also will evaluate for the first time the binding of somatostatin to liver, a major lipid depot of fish, and examine alterations in somatostatin binding characteristic (affinity, capacity) in response to nutrient (glucose) and hormonal (INS, GLU) treatment. While pertaining specifically to fish, this research will provide novel information concerning somatostatin phsyiology generally. These results will contribute significantly to the basic understanding of hormonal control of hepatic lipid metabolism and provide important insight into the evolution of lipid metabolism control schemes. ***