导管位置展示
Venous Infusion 静脉输液
Jugular V. 颈静脉 Superior Vena Cava
上腔静脉
Hepatic V. 肝静脉
Hepatic A.肝动脉
Portal V.门静脉
Gastric Infusion
Portal Infusion 门静脉灌入
Mesenteric A.肠系膜动脉 Umbilical V.脐静脉 Renal V.肾静脉 Renal A.肾动脉
Gut metabolism of amino acids : Why concern nutritionists ?
肠道内的氨基酸代谢: 为何引起营养学家的关注
The dietary requirement for some amino acids increases due to, low synthesis, increased utilization, or decreased digestibility because of :
研究项目概述
Amino acid metabolism & requirements: piglets, growing pigs and humans氨基酸代谢及营养需要: 小 猪, 生长猪以及人类。 Sow nutrition: requirements for and dietary availability of amino acids and energy母猪营养:氨基 酸与能量的母猪需求量以及日粮提供； New method for ‗true‘ amino acid availability for protein synthesis using indicator amino acid oxidation 氨基酸氧化指标——一种测定蛋白质合成 中真氨基酸利用率的新方法 Net energy values for Canadian feedstuffs加拿大饲 料净能值； Amino acid metabolism of the gut : roles in gut growth & function, immunity and protection, effect on dietary requirements 氨基酸在肠内的代谢: 对肠 道生长及功能的作用, 免疫与保护, 以及对日量需求 量的影响。
Intestinal metabolism of Aas
氨基酸的小肠代谢
The gut is a major metabolic organ.小肠是主要的代谢器官. Gut is 5-7% of body mass BUT accounts for尽管小肠只占到了
体重的5~7%，然而却占：
合成,
转运和氨基酸氧化
Amino acid metabolism by the gut氨基酸代谢——由
肠道进行
The gut uses a large percentage of dietary amino acid intake 日粮摄入的氨基酸有很大一部分是被肠道利
用的；
The gut requires amino acids for synthesis of structural proteins and enzymes 肠道利用氨基酸来合成结构蛋
Why use these Methods ?
为什么使用这样的方法？
Intravenous feeding results in gut ―atrophy‖ and loss of intestinal function 静脉营养的结果是肠道的萎缩以及
小肠功能的丧失；
IV feeding bypasses first pass metabolism by the small intestine 静脉营养法绕过了小肠的第一轮代谢； IV vs oral feeding allows us to compare AA requirements for the entire body (oral) compared to the body with inactive gut (IV) 静脉营养法相较于口服的饲喂方法可以让
Extremity末端
Femoral V.股静脉
Requirement by Indicator
Amino Acid Oxidation
氨基酸氧化指标测 定的需要量
Protein Synthesis蛋白质合成
Rate of indicator amino acid oxidation 氨基酸氧 化指标率
Breakpoint
断点
Increasing dietary intake of amino acid
增加的氨基酸日粮摄入
Effect of Route of Feeding Threonine on Requirement
饲喂途径对苏氨酸需要量的影响
DISCUSSION- Threonine 讨论——苏氨酸
Methods: Intravenous Feeding and Radioactive Tracers方法: 静脉营养和放射性元素
示踪法
2 to 3 day old male piglets2~3日龄雌性仔猪； Surgically install 4 catheters in the stomach, portal vein (liver), external jugular vein, femoral vein通过手术在胃、门静脉（肝）、颈 外静脉以及股静脉中安装4个导管。 Feed a synthetic diet either into the stomach or into a vein将一种综合性的日粮通过胃或者静 脉饲喂给动物。 At 10-12 day, measure amino acid requirement, kinetics, metabolism using radioactive tracers在10~12天的时候，通过放 射性示踪元素来测量氨基酸的需要量、动力学 以及代谢。
白和酶类
A healthy gut is required for synthesis of some amino acids (eg arginine, proline) otherwise there would be a dietary requirement ! 健康的肠道能够合成某些氨基
量的恢复期
Unhealthy Intestinal System
不良肠道系统
Healthy 健康的
Are the amino acid requirements the same ? 对氨基酸的需要量相同吗？
Novel Methods to Study AA metabolism 氨基酸代谢研究中的新方法
20-35% of whole body energy expenditure总身体能量消耗
的20-35%
20-60 % utilization of dietary amino acids日粮氨基酸的利用
率20-60 %
Intestine: synthesizes, inter-converts and oxidizes AA 小肠:
Novel advances in Amino Acid Nutrition in Piglets
仔猪氨基酸营养新进展
Dr Ron Ball
Professor Emeritus in Swine Nutrition
University of Alberta, Edmonton, Canada
Overview of Research Program
Oral THR requirement (0.55 g/kg/d) was not different from published values (0.57, NRC, 1998). 口服苏氨酸的需求量(0.55 g/kg/d)
与公布的数据没有较大差异(0.57, NRC, 1998).
THR requirement during intravenous feeding (0.20g/kg/d) was ONLY 36% of oral requirement
determined for all important amino acids.应当确定
肠道对所有重要氨基酸的需要。
Mucus in the Gut:
Critical Barrier Functions
肠道中的粘液: 关键性的功能屏障
Prevent self- digestion of intestine by enzymes
静脉注射的苏氨酸的需要量(0.20g/kg/d) 仅 是口服需要量的36%。
Bertolo et al 1998 J Nutr 128: 1752-1759
CONCLUSIONS – Threonine
结论——苏氨酸
THR requirement of the gut is substantial - 64% of whole body requirement.肠道对苏氨酸的需要量
对某些氨基酸日粮需求量的增加源于合成率较低、 利用率增加或者消化率的降低，造成这些现象的原 因是：
low feed intake采食量低 intestinal infection小肠感染 gut adaptation to new diet肠道对新日粮的适应 dietary anti-nutrients and fiber日粮中的抗营养因子以及纤维素 gut stress肠道压力 during recovery from disease or low feed intake处在疾病或者低采食
OUTLINE
概述
Reasons to study Intestinal Amino Acid Metabolism 研究肠道氨 基酸代谢的原因； Methods – Intravenous (IV) vs Intragastric (IG) feeding, amino acid oxidation, isotope tracers方法 —— 静脉注射法 (IV) 相较于 胃内喂养法(IG), 氨基酸氧化法, 同位素示踪法； Results for:结果: Threonine, Methionine, Branch-Chains, Arginine, Lysine苏 氨酸, 蛋氨酸（甲硫氨酸）, 支链氨基酸, 精氨酸, 赖氨酸