Dynamics of endogenous amino acid synthesis in pigs

猪内源氨基酸合成动力学

• 批准号: RGPIN-2015-03937
• 负责人: deLange, Cornelis
• 金额: $ 2.91万
• 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: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=589481
• 关键词: Dynamics; endogenous; amino; acid; synthesis

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.

随着人类消费对高质量食物蛋白质的需求迅速增加，人类和动物之间对替代膳食蛋白质来源的竞争也增加了。因此准确地表征蛋白质（即，氨基酸，AA;氮，N）膳食蛋白质来源的生物利用度和膳食AA需求。后者需要了解和量化的生物过程，有助于膳食AA的需求，包括动态使用不同的N源内源性合成AA。本研究的长期目标是通过更好地理解使用各种N源（必需和非必需AA，非蛋白质N）内源性合成蛋白质合成和其他代谢功能所需的条件限制性和非必需AA的动态来提高非反刍动物和人类的N利用效率。本研究旨在探讨生长猪利用上消化道和下消化道吸收的氨态氮进行蛋白质合成的动态和相对效率，以及内脏器官对氨态氮的捕获、尿素和AA净合成的动态和调节。（3）在确定的条件下苏氨酸和氨-N用于甘氨酸的内源合成的相对使用，（4）更准确地确定日粮总氮和氮源的需要量，以满足内源AA合成的需要，优化非必需AA N缺乏日粮中生长猪的氮利用。本研究将通过一系列内脏器官质量平衡和同位素示踪研究来定量测定生长猪内源性AA的合成，并探讨其调控机制。这些研究将补充酶动力学和基因表达测定，消化率和氮平衡观察，以及统计和数学（建模）分析。拟议中的研究将产生急需的定量信息内源性AA合成时，猪饲喂的饮食是轻微缺乏非必需的AA N和提高我们的理解AA代谢的基本方面在非反刍动物和人类。最终，这项研究将提高非反刍动物和人类对膳食氮的利用率，减少有害氮在环境中的损失，并增加使用替代蛋白质来源作为饲料和食品的灵活性。拟议的研究还将有助于培养高素质的人才。