Oxidation of amino acids by diaphragms from fed and fasted rats.
Oxidation of amino acids by diaphragms from fed and fasted rats.
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进食和禁食大鼠的隔膜对氨基酸的氧化。
DOI：
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发表时间：
1972
影响因子：
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通讯作者：
R. Odessey
中科院分区：
文献类型：
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作者：
A. Goldberg;R. Odessey
阿尔弗雷德·戈德堡和理查德·奥德赛。饲喂和禁食大鼠膈膜对氨基酸的氧化作用。点。[j] .中国生物医学工程学报，2009(6):394 - 394。1972.-研究了l -氨基- 14c酸在饲养和禁食大鼠分离膈肌中的氧化作用。在90分钟的孵育过程中，喂食大鼠的膈膜产生的14co2由亮氨酸-14C、异亮氨酸-14C、缬氨酸-14C、丙氨酸-14C、谷氨酸- u -14C和天冬氨酸- u -14C产生，其速率与它们将标签转化为蛋白质的速率相当或更高。相比之下，肌肉分解为二氧化碳的甘氨酸、丝氨酸和脯氨酸只有不到5%进入组织，而苏氨酸、赖氨酸、蛋氨酸、苯丙氨酸、组氨酸、酪氨酸和色氨酸则没有。在禁食3天的动物膈肌中，蛋白质合成比对照组低50%，而亮氨酸、异亮氨酸和缬氨酸的氧化增加了3 - 5倍。这些氨基酸进入隔膜的总摄取也增加了。氨基酸掺入量在剥夺食物后1天内明显下降，但氨基酸氧化量直到第2天才增加。在较宽的亮氨酸浓度范围内，这种膜中的亮氨酸氧化率较高。禁食动物重新喂食后，膈肌蛋白质合成增加，亮氨酸分解代谢在24小时内降至控制值。在饥饿大鼠的肾脏切片中也观察到亮氨酸分解代谢增加，但在肝脏和大脑切片中没有。提示肾脏和肌肉降解支链氨基酸能力的增强是对饥饿的重要适应。
GOLDBERG, ALFRED L., AND RICHARD ODESSEY. Oxidation of amino acids by diaphragms from fed and fasted rats. Am. J. Physiol. 223(6) : 1384-1391. 1972.-The oxidation of L-amino-14C acids was studied in isolated diaphragms from fed and fasted rats. During a 90-min incubation, diaphragms from fed rats produced 14C02 from leucinel14C, isoleucine1 -14C, valine1 -14C, alanineP4C, glutamate-U-14C, and aspartate-U-14C at a comparable or greater rate than they incorporated label into protein. By contrast, muscle degraded to CO2 less than 5% of the glycine, serine, and proline entering the tissue and none of the threonine, lysine, methionine, phenylalanine, histidine, tyrosine, and tryptophan. In diaphragms of animals fasted for 3 days, protein synthesis was 50% lower than control values, whereas oxidation of leucine, isoleucine, and valine increased three-to fivefold. Total uptake of these amino acids into the diaphragm also increased. The fall in amino acid incorporation was evident within 1 day after food deprivation, but amino acid oxidation did not increase until the 2nd day. A greater rate of leucine oxidation in such diaphragms occurred over a wide range of leucine concentrations. Upon refeeding the fasted animals, protein synthesis in the diaphragm increased and leucine catabolism decreased to control values within 24 hr. Increased leucine catabolism was also observed in kidney slices from the starved rats but not in liver or brain slices. It is suggested that the increased capacity of kidney and muscle to degrade branched-chain amino acids is an important adaptation to starvation.