Impairment of phenylalanine conversion to tyrosine inend-stage renal disease causing tyrosine deficiency
| Autor: | K. Sreekumaran Nair, Maureen N Bigelow, Robert C. Albright, Yves Boirie |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Nephrology
Adult medicine.medical_specialty renal failure Hydrocortisone phenylalanine muscle Phenylalanine End stage renal disease Internal medicine medicine Humans Insulin Tyrosine Insulin-Like Growth Factor I Aged chemistry.chemical_classification Kidney hemodialysis Nitrogen Isotopes business.industry Middle Aged medicine.disease Deuterium Amino acid Protein catabolism Endocrinology medicine.anatomical_structure chemistry Kidney Failure Chronic business tyrosine Kidney disease |
| Zdroj: | Kidney International. 66(2):591-596 |
| ISSN: | 0085-2538 |
| DOI: | 10.1111/j.1523-1755.2004.00778.x |
| Popis: | Impairment of phenylalanine conversion to tyrosine in end-stage renal disease causing tyrosine deficiency.BackgroundTyrosine is not considered an indispensable amino acid because in humans phenylalanine is converted to tyrosine. Recent human studies demonstrated that tyrosine production from phenylalanine occurs not only in liver but also in kidney.MethodsHere we report results from studies, performed in end-stage renal disease (ESRD) patients and in healthy controls using [15N] phenylalanine and [2H4] tyrosine as tracers demonstrating the mechanism of tyrosine deficiency in patients with renal failure.ResultsPhenylalanine flux (an index of protein breakdown) was identical in both groups either before or during an infusion of amino acid mixture. In contrast, tyrosine flux (representing protein breakdown and tyrosine appearance from phenylalanine) and conversion of phenylalanine to tyrosine were lower in ESRD patients [2.05 ± 0.30 μmol/kg fat-free mass (FFM)/hour and 2.59 ± 0.52 μmol/kg FFM/hour, before and during amino acid infusion, respectively] than in the control subjects (4.07 ± 0.54 μmol/kg FFM/hour and 5.53 ± 0.86 μmol/kg FFM/hour, P |
| Databáze: | OpenAIRE |
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