Glycylglutamine: metabolism and effects on organ balances of amino acids in postabsorptive and starved subjects.
Glycylglutamine: metabolism and effects on organ balances of amino acids in postabsorptive and starved subjects.
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甘氨酰谷氨酰胺：吸收后和饥饿受试者中氨基酸的代谢及其对器官平衡的影响。
DOI：
10.1152/ajpendo.1992.262.2.e155
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Adibi,SA
中科院分区：
文献类型：
--
作者：
Lochs,H;Hubl,W;Gasic,S;Roth,E;Morse,EL;Adibi,SA
本研究旨在研究甘氨酰谷氨酰胺在人体吸收后和短暂饥饿(84~86h)时的代谢及其对人体器官氨基酸平衡的影响。吸收后(265+/-18微米)和饥饿(241+/-13微米)受试者的动脉甘氨酰谷氨酰胺浓度没有显著差异。在所检查的器官中，肾脏对血浆中甘氨酰谷氨酰胺的清除占主导地位。此外，饥饿降低了甘氨酰谷氨酰胺在肾脏的清除(87+/-7vs.52+/-5mumol/min，P<0.01)，而内脏和肌肉的清除都没有受到明显影响。输注甘氨酰谷氨酰胺通过增加肾脏释放甘氨酸和谷氨酰胺来增加血浆中甘氨酸和谷氨酰胺的浓度。在吸收后的受试者中，输液显着增加内脏甘氨酸和谷氨酰胺的平衡，而对肌肉平衡几乎没有影响；在饥饿的受试者中发现相反的情况。就其他氨基酸而言，输液减少了肌肉丙氨酸的释放，增加了肾脏丝氨酸的释放。我们的结论是，甘氨酰谷氨酰胺的氨基酸残基在吸收后的受试者内脏器官和饥饿受试者的外周器官中大量代谢。后者导致选择性地抑制肌肉中氨基酸的释放。
The present study was designed to investigate the metabolism of glycylglutamine and its effects on organ balances of amino acids during intravenous infusion of this dipeptide (100 mumol.h-1.kg-1) in postabsorptive and briefly starved (84-86 h) human subjects. Arterial concentrations of glycylglutamine were not significantly different in postabsorptive (265 +/- 18 microM) and starved (241 +/- 13 microM) subjects. Among the organs examined, kidney predominated in clearance of glycylglutamine from plasma. Moreover, renal clearance of glycylglutamine was reduced by starvation (87 +/- 7 vs. 52 +/- 5 mumol/min, P less than 0.01), whereas neither splanchnic nor muscle clearance was significantly affected. Infusion of glycylglutamine raised plasma concentrations of glycine and glutamine by increasing renal release of these amino acids. In postabsorptive subjects the infusion significantly increased splanchnic balances of glycine and glutamine with little or no effect on the muscle balances; the opposite was found in starved subjects. As far as other amino acids are concerned, the infusion decreased the muscle release of alanine and increased renal release of serine. We conclude that the amino acid residues of glycylglutamine are largely metabolized by the splanchnic organs in postabsorptive subjects and by peripheral organs in starved subjects. The latter results in selective inhibition of muscle release of amino acids.