Dynamics and regulation of endogenous amino acid synthesis in pigs

猪内源氨基酸合成的动态和调控

• 批准号: RGPIN-2016-04496
• 负责人: deLange, Cornelis
• 金额: $ 3.42万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=615102
• 关键词: Dynamics; regulation; endogenous; amino; acid

With the rapidly increasing demand for high quality food protein for human consumption, competition between humans and animals for alternative dietary protein sources has increased. It is thus important to accurately characterize protein (i.e., amino acids, AA; nitrogen, N) bioavailability in dietary protein sources and dietary AA requirements. The latter requires an understanding and quantification of the biological processes that contribute to dietary AA requirements, including dynamics of using different N sources for endogenous synthesis of AA. The long term aim of this research is to improve N utilization efficiency in non-ruminant animals and humans through improved understanding of the dynamics of using various N sources (essential and non-essential AA, non-protein N) for the endogenous synthesis of conditionally limiting and non-essential AA that are needed for protein synthesis and other metabolic functions. The research objectives are to explore in the growing pig: (1) dynamics and relative efficiency of using ammonia-N absorbed from either the upper or lower gut for body protein synthesis; (2) dynamics and regulation of ammonia-N capturing, as well as urea and net AA synthesis in visceral organs; (3) relative use of threonine and ammonia-N for the endogenous synthesis of glycine under defined conditions, and (4) more accurately define dietary requirements for total N and N-sources to satisfy needs for endogenous AA synthesis for optimizing N utilization in growing pigs fed diets deficient in non-essential AA N. A series of visceral organ mass balance and isotope tracer studies will be conducted to quantify endogenous AA synthesis in (surgically modified) growing pigs, and explore its regulation. These studies will be complemented with enzyme kinetics and gene expression assays, digestibility and N-balance observations, as well as statistical and mathematical (modelling) analyses. The proposed research will yield much needed quantitative information about endogenous AA synthesis when pigs are fed diets that are marginally deficient in non-essential AA N and improve our understanding of basic aspects of AA metabolism in non-ruminant animals and humans. Ultimately this research will lead to improved utilization of dietary N in both non-ruminant animals and humans, reducing losses of harmful N into the environment, as well as increased flexibility in the use of alternative protein sources for feed and food. The proposed research will also contribute to training of highly qualified personnel.

随着人类对高品质食品蛋白质需求的迅速增加，人类和动物之间对替代膳食蛋白质来源的竞争日益激烈。因此，准确表征蛋白质（即氨基酸，AA；氮，N）在饲料蛋白质来源中的生物利用度和饲料中AA的需要量是很重要的。后者需要了解和量化影响饲粮AA需求的生物学过程，包括使用不同氮源进行AA内源合成的动态。本研究的长期目标是提高非反刍动物和人类利用各种氮源（必需和非必需AA、非蛋白N）内源合成蛋白质合成和其他代谢功能所需的有条件限制性和非必需AA的动态，从而提高氮的利用效率。研究目的是探讨生长猪利用上、下肠道吸收的氨氮合成机体蛋白质的动态和相对效率；(2)内脏器官中氨氮捕获、尿素和净AA合成的动态与调控；(3)确定条件下苏氨酸和氨氮在甘氨酸内源合成中的相对用量；(4)更准确地确定饲粮对总氮和氮源的需求，以满足饲粮中缺乏非必需氨基酸的生长猪对内源氨基酸合成的需求，从而优化生长猪对氮的利用。并探讨其规律。这些研究将辅以酶动力学和基因表达分析，消化率和n平衡观察，以及统计和数学（建模）分析。本研究将提供猪饲粮中非必需氨基酸些微缺乏时内源性氨基酸合成的定量信息，并提高我们对非反刍动物和人类氨基酸代谢基本方面的认识。最终，这项研究将提高非反刍动物和人类对饲粮氮的利用，减少有害氮在环境中的损失，并增加饲料和食品中替代蛋白质来源的灵活性。拟议的研究也将有助于训练高度合格的人员。