Alleviation of body weight loss by dietary methionine is independent of insulin-like growth factor-I in protein-starved young chickens
Alleviation of body weight loss by dietary methionine is independent of insulin-like growth factor-I in protein-starved young chickens
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DOI：
10.1111/j.1740-0929.2010.00868.x
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发表时间：
2011-01-01
影响因子：
2
通讯作者：
Kita, Kazumi
中科院分区：
文献类型：
--
作者：
Nagao, Kenji;Oki, Mai;Kita, Kazumi
众所周知，在蛋白质饥饿的鸡中，少量补充氨基酸，特别是蛋氨酸，可以减少氮排泄，从而改善氮平衡。另一方面，过量摄入蛋氨酸会导致生长抑制，过量摄入蛋氨酸可以通过补充甘氨酸来缓解这种生长抑制作用。胰岛素样生长因子- i （IGF-I）是与动物生产效率相关的多种生长促进因子之一，对营养状况的变化非常敏感。在本研究中，研究了甘氨酸对蛋白质饥饿鸡蛋氨酸节约氮作用的交互作用。此外，还研究了IGF-I及其特异性结合蛋白与补充蛋氨酸的氮节约效应的关系。在无蛋白饲粮中补充蛋氨酸2 d可迅速缓解蛋白质饥饿鸡的体重减轻，而补充甘氨酸不能改善蛋氨酸对体重减轻的作用。此外，膳食蛋氨酸对体重减轻的这种急性缓解与血浆IGF-I浓度的变化无关。
It is well known that in protein-starved chickens, small amounts of amino acid supplement, especially methionine, reduces nitrogen excretion and thereby improves nitrogen balance. On the other hand, excess intake of methionine causes growth depression and the growth-depressive effect of excess methionine can be alleviated by consumption of dietary glycine. Insulin-like growth factor-I (IGF-I) is one of various growth-promoting factors relating to the efficiency of animal production and is known to be very sensitive to changes in nutritional status. In the present study, the interactive effect of glycine on nitrogen sparing effect of methionine in protein-starved chickens was examined. In addition, the relation of IGF-I and its specific binding protein to the nitrogen sparing effect of supplemented methionine was also investigated. Two-days refeeding of methionine supplemented to protein-free diet could promptly alleviate body weight loss in protein-starved chickens, and the alleviation of body weight loss by methionine was not improved by glycine supplements. Moreover, such acute alleviation of body weight loss by dietary methionine was independent of the change in plasma IGF-I concentration.