Tharakan John F, Yu Yong M, Zurakowski David, Roth Rachel M, Young Vernon R, Castillo Leticia
Laboratory of Human Nutrition and Clinical Research Center, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
Clin Nutr. 2008 Aug;27(4):513-22. doi: 10.1016/j.clnu.2008.04.014. Epub 2008 Jun 30.
BACKGROUND & AIMS: It is not known whether arginine homeostasis is negatively affected by a "long term" dietary restriction of arginine and its major precursors in healthy adults. To assess the effects of a 4-week arginine- and precursor-free dietary intake on the regulatory mechanisms of arginine homeostasis in healthy subjects.
Ten healthy adults received a complete amino acid diet for 1 week (control diet) and following a break period, six subjects received a 4-week arginine, proline, glutamate and aspartate-free diet (APF diet). The other four subjects continued for 4 weeks with the complete diet. On days 4 and 7 of the first week and days 25 and 28 of the 4-week period, the subjects received 24-h infusions of arginine, citrulline, leucine and urea tracers.
During the 4-week APF, plasma arginine fluxes for the fed state, were significantly reduced. There were no significant differences for citrulline, leucine or urea fluxes. Arginine de novo synthesis was not affected by the APF intake. However, arginine oxidation was significantly decreased.
In healthy adults, homeostasis of arginine under a long term arginine- and precursor-free intake is achieved by decreasing catabolic rates, while de novo arginine synthesis is maintained.
尚不清楚在健康成年人中，精氨酸及其主要前体的“长期”饮食限制是否会对精氨酸稳态产生负面影响。为评估4周无精氨酸及前体饮食摄入对健康受试者精氨酸稳态调节机制的影响。
10名健康成年人先接受1周的全氨基酸饮食（对照饮食），在一段间隔期后，6名受试者接受4周无精氨酸、脯氨酸、谷氨酸和天冬氨酸的饮食（APF饮食）。另外4名受试者继续4周的全饮食。在第一周的第4天和第7天以及4周期间的第25天和第28天，受试者接受精氨酸、瓜氨酸、亮氨酸和尿素示踪剂的24小时输注。
在4周的APF饮食期间，进食状态下的血浆精氨酸通量显著降低。瓜氨酸、亮氨酸或尿素通量无显著差异。精氨酸从头合成不受APF饮食摄入的影响。然而，精氨酸氧化显著降低。
在健康成年人中，长期无精氨酸及前体摄入时，精氨酸稳态是通过降低分解代谢率实现的，同时精氨酸从头合成得以维持。
