Glucose and insulin effects on the novo amino acid synthesis in young men: studies with stable isotope labeled alanine, glycine, leucine, and lysine.
Glucose and insulin effects on the novo amino acid synthesis in young men: studies with stable isotope labeled alanine, glycine, leucine, and lysine.
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葡萄糖和胰岛素对年轻男性新氨基酸合成的影响：用稳定同位素标记的丙氨酸、甘氨酸、亮氨酸和赖氨酸进行的研究。
DOI：
10.1016/0026-0495(82)90006-3
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
Young,VR
中科院分区：
文献类型：
--
作者：
Robert,JJ;Bier,DM;Zhao,XH;Matthews,DE;Young,VR
我们已经探索了成人全身葡萄糖和丙氨酸和甘氨酸代谢的动态方面之间的相互关系。使用引发，连续静脉输注的[1- 13 C]亮氨酸或赖氨酸同时给予[2 H3]或[15 N]丙氨酸或[15 N]甘氨酸，分别，全身丙氨酸和甘氨酸通量和从头合成率进行了测定，在三个实验与健康的年轻男子。受试者在吸收后状态下和以4 mg.kg-1 min-1的速率静脉输注未标记葡萄糖150 min期间接受研究。在一项实验中，胰岛素与葡萄糖输注一起给予以维持正常血糖。在另外两项研究中，受试者仅接受葡萄糖。对于吸收后状态，在两个单独的实验中，丙氨酸通量（平均值± SEM）为381 ± 26和317 ± 18 μ mol.kg −1hr− 1，甘氨酸通量为240 ± 22 μ mol.kg −1hr−1。丙氨酸和甘氨酸的从头合成分别占通量的75%-81%和81%。单独输注葡萄糖使血浆葡萄糖平均水平升高至152 mg/dl，并增加丙氨酸通量，这是由于丙氨酸合成增加了98 μmole.kg-1hr-1（p< 0.01）。甘氨酸通量和合成速率不受葡萄糖输注的影响。当胰岛素与葡萄糖一起使用以维持正常血糖时，丙氨酸合成速率不变。因为无论葡萄糖是与外源性胰岛素一起沿着输注还是与外源性胰岛素一起输注，用[6，6 - 2 H2]葡萄糖测量的葡萄糖摄取率都是相同的，所以这些结果支持这样的观点，即循环血浆葡萄糖水平本身可能影响丙氨酸合成，并且高血糖状态是在各种病理生理状态下调节器官间氮转移（通过丙氨酸）的重要因素。
We have explored interrelationships between the dynamic aspects of whole body glucose and alanine and glycine metabolism in adult humans. Using a primed, continuous intravenous infusion of [1-13C] leucine or lysine given simultaneously with [2H3] or [15N]alanine or [15N]glycine, respectively, whole body alanine and glycine fluxes and their rates of de novo synthesis were determined in three experiments with healthy young men. Subjects were studied in the post-absorptive state and during a 150 min period of an intravenous infusion with unlabeled glucose, at a rate of 4 mg.kg−1min−1. In one experiment, insulin was given together with the glucose infusion to maintain normoglycemia. In the other two studies, subjects received glucose alone. For the post-absorptive state, alanine flux (mean ± SEM) was 381 ± 26 and 317 ± 18 μmole.kg−1hr−1in two separate experiments and glycine flux was 240 ± 22 μmole.kg−1hr−1. De novo synthesis of alanine and glycine accounted for 75%–81% and 81% of flux, respectively. Infusion with glucose alone raised plasma glucose to a mean level of 152 mg/dl and increased alanine flux, due to a rise in alanine synthesis of 98 μmole.kg−1hr−1(p< 0.01). Glycine flux and synthesis rate were unaffected by the glucose infusion. When insulin was given with glucose to maintain normoglycemia, the rate of alanine synthesis was unchanged. Because glucose uptake rate, measured with [6,6−2H2] glucose was the same whether glucose was infused along or with exogenous insulin, these results support the view that the circulating plasma glucose level itself may affect alanine synthesis and that the hyperglycemic state is an important factor in regulating interorgan nitrogen transfer, via alanine, in various pathophysiologic states.