The branched-chain amino acid antagonism in chicks.
The branched-chain amino acid antagonism in chicks.
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雏鸡中的支链氨基酸拮抗作用。
DOI：
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发表时间：
1978
期刊：
影响因子：
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通讯作者：
R. E. Austic
中科院分区：
文献类型：
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作者：
T. Smith;R. E. Austic
研究了日粮中添加支链氨基酸对雏鸡生长、摄食和代谢的影响。当足够的饮食含有1.20，1.60，2.25，3.75，或5.00%的亮氨酸，增加亮氨酸含量导致减少的食物消耗和体重增加，加上受损的食物利用效率。当饮食中缺乏支链氨基酸含有0.98，1.46，2.25，3.75，或5.00%的亮氨酸，增加亮氨酸导致增加的食物消耗和减少的食物利用效率时，亮氨酸水平高达3.75%的饲料。过量的亮氨酸降低血浆中异亮氨酸和缬氨酸的浓度。过量的异亮氨酸或缬氨酸引起的其他两个支链氨基酸的浓度较小的凹陷。所有这些影响都在实验的前8天出现，之后它们减弱或消失。肌肉支链氨基酸氨基转移酶（BCAT）（L-亮氨酸：2-酮戊二酸氨基转移酶，EC 2.6.1.6）的活性增加，在鸡饲料中过量亮氨酸，但不是在那些饲料中过量异亮氨酸或缬氨酸。肝脏α-酮异己酸脱氢酶（KADH）（2-氧代异己酸：硫辛酸氧化还原酶，EC 1.2.4.3）活性和肌肉多聚核糖体聚集不受饮食影响。当雏鸡饲喂含0.98%或2.25%亮氨酸的日粮时，饲喂较高水平亮氨酸的雏鸡从[1- 14 C]异亮氨酸和[1- 14 C]缬氨酸产生的14 CO2增加。在这两种情况下增加的幅度都很小，约占消耗的异亮氨酸和缬氨酸的2%。在喂食过量亮氨酸的12小时内观察到14 CO2的产生增加;然而，BCAT仅在2至4天后增加。在排泄的14 C或14 C沿小肠沿着的相对分布中未观察到差异。我们的结论是，小鸡是能够适应部分过量的饮食亮氨酸和支链氨基酸的拮抗作用可能涉及增加限制支链氨基酸的catenosine。
The effects of dietary supplements of branched-chain amino acids on growth, food consumption and metabolism in chicks were investigated. When an adequate diet contained 1.20, 1.60, 2.25, 3.75, or 5.00% leucine, increasing leucine content caused reduced food consumption and weight gains, coupled with impaired efficiency of food utilization. When the diet deficient in branched-chain amino acids contained 0.98, 1.46, 2.25, 3.75, or 5.00% leucine, increasing leucine resulted in increased food consumption and reduced efficiency of food utilization when levels of leucine up to 3.75% were fed. Excess leucine depressed plasma concentrations of isoleucine and valine. Excesses of isoleucine or valine caused smaller depressions of concentrations of the other two branched-chain amino acids. All these effects were seen during the first 8 days of experiment, after which they diminished or disappeared. Muscle branched-chain amino acid aminotransferase (BCAT) (L-leucine:2-oxoglutarate aminotransferase, EC 2.6.1.6) activity was increased in chicks fed excess leucine but not in those fed excess isoleucine or valine. Hepatic alpha-ketoisocaproic dehydrogenase (KADH) (2-oxoisocaproate:lipoate oxidoreductase, EC 1.2.4.3) activity and muscle polyribosomal aggregation were unaffected by diet. When chicks were fed diets containing either 0.98 or 2.25% leucine, production of 14CO2 from [1-14C]isoleucine and [1-14C]valine was increased in chicks fed the higher level of leucine. The increase was small in both cases, representing approximately 2% of consumed isoleucine and valine. Increased production of 14CO2 was observed within 12 hours of feeding excess leucine; however, BCAT increased only after 2 to 4 days. No differences were seen in excreted 14C or in the relative distribution of 14C along the small intestine. We conclude that the chick is able to adapt in part to excesses of dietary leucine and that the branched-chain amino acid antagonism may involve increased catabolism of the limiting branched-chain amino acids.