Adaptation to a long term (4 weeks) arginine- and precursor (glutamate, proline and aspartate)-free diet

• Published in: Clinical nutrition (Edinburgh, Scotland) Vol. 27; no. 4; pp. 513 - 522
• Main Authors: Tharakan, John F, Yu, Yong M, Zurakowski, David, Roth, Rachel M, Young, Vernon R, Castillo, Leticia
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.08.2008; Elsevier
• Subjects: Adult; Analysis of Variance; Arginine; Arginine - administration & dosage; Arginine - deficiency; Arginine - metabolism; Aspartic Acid - administration & dosage; Aspartic Acid - deficiency; Aspartic Acid - metabolism; Biological and medical sciences; Carbon Isotopes; Citrulline - metabolism; Diet; Dietary Proteins - administration & dosage; Feeding. Feeding behavior; Female; Fundamental and applied biological sciences. Psychology; Gastroenterology and Hepatology; Glutamic Acid - administration & dosage; Glutamic Acid - deficiency; Glutamic Acid - metabolism; Homeostasis; Humans; Infusions, Intravenous; Isotope Labeling - methods; Kinetics; Leucine - metabolism; Male; Metabolism; Nitrogen Isotopes; Oxidation; Oxidation-Reduction; Proline - administration & dosage; Proline - deficiency; Proline - metabolism; Stable isotopes; Synthesis; Time Factors; Urea - metabolism; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Synthesis; Arginine; Stable isotopes; APF; Oxidation; arginine- and precursor-free; Metabolism; Deficient diet; Excitatory aminoacid; Neurotransmitter; Proline; Metabolic diseases; Glutamate; Long term; Precursor; Feeding; Adaptation
• ISSN: 0261-5614; 1532-1983
• DOI: 10.1016/j.clnu.2008.04.014

Summary 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. Methods 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. Results 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. Conclusions 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.