Hambraeus L, Bilmazes C, Dippel C, Scrimshaw N, Young V R
J Nutr. 1976 Feb;106(2):230-40. doi: 10.1093/jn/106.2.230.
Four healthy young men were studied to explore the effects of dietary leucine intake on plasma levels of leucine,isoleucine and valine. Leucine-, valine-, leucine-valine-, and leucine-isoleucine-valine-free amino acid mixtures were studied during four-day experimental diet periods. The effects of giving amino acid mixtures with high-carbohydrate, low-fat or low-carbohydrate, high-fat diets were also studied. Deficient leucine intake increased plasma levels of valine and isoleucine, but a valine-free diet did not affect plasma levels of the other branched-chain amino acids. Leucine influence was evident during the postprandial and fasted phases. Valine and isoleucine levels were less markedly reduced when diets devoid of these amino acids were also leucine-free, as compared with a diet providing adequate leucine. Changes in the major dietary energy source failed to influence the qualitative effects of dietary leucine adequacy on the branched-chain amino acid levels in plasma. The results suggest that leucine facilitates both tissue uptake of branched-chain amino acids and their intracellular metabolism.
对四名健康年轻男性进行了研究，以探讨膳食亮氨酸摄入量对血浆亮氨酸、异亮氨酸和缬氨酸水平的影响。在为期四天的实验饮食期间，研究了不含亮氨酸、缬氨酸、亮氨酸 - 缬氨酸以及亮氨酸 - 异亮氨酸 - 缬氨酸的氨基酸混合物。还研究了给予高碳水化合物、低脂或低碳水化合物、高脂肪饮食的氨基酸混合物的效果。亮氨酸摄入不足会增加血浆缬氨酸和异亮氨酸水平，但不含缬氨酸的饮食对其他支链氨基酸的血浆水平没有影响。亮氨酸的影响在餐后和禁食阶段都很明显。与提供充足亮氨酸的饮食相比，当不含这些氨基酸的饮食也不含亮氨酸时，缬氨酸和异亮氨酸水平的降低不太明显。主要膳食能量来源的变化未能影响膳食亮氨酸充足对血浆中支链氨基酸水平的定性影响。结果表明，亮氨酸促进了支链氨基酸的组织摄取及其细胞内代谢。
