Regulation of Intestinal Function in a Mammalian Hibernator

哺乳动物冬眠者肠道功能的调节

• 批准号: 9306813
• 负责人: Hannah Carey
• 金额: $ 25.5万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-07-01 至 1997-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9306813&HistoricalAwards=false
• 关键词: Regulation; Intestinal; Function; Mammalian; Hibernator

9306813 Carey The overall goal of this 3-year project is to increase understanding of regulatory signals underlying changes in intestinal function during the seasonal cycle of a mammalian hibernator, the 13-lined ground squirrel. Previous studies in the applicant's laboratory have documented structural and functional changes in small intestinal tissues of ground squirrels that are closely related to the seasonal cycles of food intake and metabolic activity in these animals. During the proposed project period, we plan to extend our earlier findings and determine how digestive enzyme and nutrient transport function are regulated during the different activity phases of ground squirrels. This objective will be met by focusing on four areas: (1) characterization of sugar and amino acid transport at the level of the brush border membrane; (2) immunocytochemical localization of Na+-glucose transporter and sucrase-isomaltase proteins in intestinal tissues; (3) determination of intestinal epithelial cell age and migration rates in hibernating and active squirrels; (4) determination of messenger RNA levels coding for NA+-glucose transporter and sucrase-isomaltase proteins during specific activity states of the squirrels. This project will directly address the increasing evidence (in non-hibernating species) that the presence of luminal substrate is required for maximal expression of nutrient transporters on brush border membranes, by studying a mammal that has been shaped by adaptive evolution to forego feeding for long periods of time. Together, these studies should provide a comprehensive picture that characterizes the regulation of nutrient digestive and transport function on multiple levels. Information gained from this study will increase our understanding of the ability of intestinal transport systems to adapt to dramatic changes in food resources in a seasonal environment. ***

9306813 Carey这个3年项目的总体目标是在哺乳动物冬眠（13衬里的地松鼠）的季节性周期中增加对肠功能变化的监管信号的理解。 先前在申请人实验室进行的研究证明了地松鼠的小肠道组织的结构和功能变化与这些动物的食物摄入季节和代谢活性密切相关。 在拟议的项目期间，我们计划扩展我们的早期发现，并确定在地松鼠的不同活性阶段如何调节消化酶和营养运输功能。 通过关注四个区域：（1）在刷子边界膜水平上的糖和氨基酸转运的表征； （2）肠道组织中Na+ - 葡萄糖转运蛋白和Sucrase-异藻酶蛋白的免疫细胞化学定位； （3）确定冬眠和活跃松鼠中肠上皮细胞的年龄和迁移率； （4）在松鼠的特定活性态期间，确定Na+ - 葡萄糖转运蛋白和Sucrase-异晶酶蛋白编码的信使RNA水平。 该项目将直接解决越来越多的证据（在非释放物种中）表明，腔底物的存在是通过研究一种哺乳动物在长时间喂养的哺乳动物上，需要在刷子边界膜上最大表达营养转运蛋白。 总之，这些研究应提供一份全面的图片，以多个级别的养分消化和运输功能进行调节。 从这项研究中获得的信息将增加我们对肠道运输系统适应季节性环境中食品资源发生巨大变化的能力的理解。 ***