Arginine and ornithine kinetics in severely burned patients: increased rate of arginine disposal
| Autor: | V. R. Young, Leticia Castillo, Ronald G. Tompkins, Colleen M. Ryan, Xiao-Ming Lu, Yong Ming Yu, Louis Beaumier |
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| Rok vydání: | 2001 |
| Předmět: |
Adult
Male Ornithine medicine.medical_specialty Burn injury Proline Arginine Physiology Endocrinology Diabetes and Metabolism Biology chemistry.chemical_compound Biosynthesis Leucine Physiology (medical) Internal medicine medicine Humans Aged Aged 80 and over Carbon Isotopes Nitrogen Isotopes Metabolism Middle Aged Deuterium Arginase De novo synthesis Kinetics Endocrinology chemistry Female Parenteral Nutrition Total Burns Oxidation-Reduction |
| Zdroj: | American Journal of Physiology-Endocrinology and Metabolism. 280:E509-E517 |
| ISSN: | 1522-1555 0193-1849 |
| DOI: | 10.1152/ajpendo.2001.280.3.e509 |
| Popis: | Arginine serves multiple roles in the pathophysiological response to burn injury. Our previous studies in burn patients demonstrated a limited net rate of arginine de novo synthesis despite a significantly increased arginine turnover (flux), suggesting that this amino acid is a conditionally indispensable amino acid after major burns. This study used [15N2-guanidino-5,5-2H2]arginine and [5-13C]ornithine as tracers to assess the rate of arginine disposal via its conversion to and subsequent oxidation of ornithine; [5,5-2H2]proline and [5,5,5-2H3]leucine were also used to assess proline and protein kinetics. Nine severely burned patients were studied during a protein-free fast (“basal” or fast) and total parenteral nutrition (TPN) feedings. Compared with values from healthy volunteers, burn injury significantly increased 1) fluxes of arginine, ornithine, leucine, and proline; 2) arginine-to-ornithine conversion; 3) ornithine oxidation; and 4) arginine oxidation. TPN increased arginine-to-ornithine conversion and proportionally increased irreversible arginine oxidation. The elevated arginine oxidation, with limited net de novo synthesis from its immediate precursors, further implies that arginine is a conditionally indispensable amino acid in severely burned patients receiving TPN. |
| Databáze: | OpenAIRE |
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