Influence of dietary potassium on lysine metabolism in the chick.
Influence of dietary potassium on lysine metabolism in the chick.
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日粮钾对雏鸡赖氨酸代谢的影响。
DOI：
10.1093/jn/108.1.137
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发表时间：
1978
期刊：
影响因子：
--
通讯作者：
R. E. Austic
中科院分区：
文献类型：
--
作者：
R. L. Scott;R. E. Austic
据报道，高水平的膳食阳离子可以使饲喂含有过量赖氨酸的膳食的雏鸡免于精氨酸需求。目前的研究进行，以确定这种影响的性质，使用钾作为可变阳离子。在高赖氨酸饲料中添加1.8%的钾可改善生长，但不会持续影响饲料利用效率，也不会对通过肾脏精氨酸酶活性、尿素排泄或精氨酸排泄测量的精氨酸代谢产生显着影响。然而，赖氨酸催化剂显著增加。在6小时内，饲喂钾补充饲料的雏鸡将约23%的14 C赖氨酸口服负荷剂量转化为呼吸性14 CO2，而饲喂含0.4%钾的未补充饲料的雏鸡约为9%。肝脏赖氨酸-α-酮戊二酸还原酶的活性，在赖氨酸的catalysis的初始酶，增加钾或精氨酸补充。有人提出，高水平的钾或其他阳离子可以通过增加赖氨酸催化剂来改善饲喂含有过量赖氨酸的日粮的雏鸡的生长。对生长的影响可能主要通过增加食物摄入来介导，在较小程度上通过减轻赖氨酸-精氨酸拮抗作用的其他代谢表现来介导。
High levels of dietary cations have been reported to spare the arginine requirement of chicks fed a diet containing excess lysine. The present studies were conducted to determine the nature of this effect, using potassium as the variable cation. The inclusion of 1.8% potassium in a high lysine diet improved growth but did not affect consistently the efficiency of feed utilization, nor did it have a significant effect on arginine metabolism as measured by renal arginase activity, urea excretion or arginine excretion. Lysine catabolism was markedly increased, however. Chicks fed the potassium supplemented diet converted approximately 23% of an oral loading dose of 14C lysine to respiratory 14CO2 over a 6-hour period, in contrast to approximately 9% of the dose in chicks fed the unsupplemented diet containing 0.4% potassium. The activity of hepatic lysine-alpha-ketoglutarate reductase, an initial enzyme in the catabolism of lysine, was increased in response to potassium or arginine supplementation. It is proposed that high levels of potassium or other cations may improve the growth of chicks fed diets containing excess lysine by increasing lysine catabolism. The effect on growth may be mediated primarily by increasing food intake and to a lesser extent by alleviation of the other metabolic manifestation of the lysine-arginine antagonism.