title: N-acetyl-L-tyrosine as a tyrosine source in adult parenteral nutrition.
abstract: BACKGROUND
  N-acetyl-L-tyrosine (NAT) is commonly used in place of tyrosine in parenteral nutrition, but human studies carried out to date indicate considerable amounts of it are excreted unchanged in the urine. NAT retention has not been well studied in parenterally fed adults.
  
  
  METHODS
  NAT retention was measured in 13 adults receiving continuous parenteral nutrition with Aminosyn II 15% (Abbott Laboratories, Abbott Park, IL).
  
  
  RESULTS
  Approximately 35% of administered NAT was excreted unchanged in the urine, with no important effect of infusion rate, N balance, or level of renal function on this value. Sufficient NAT was retained that the prescription of 1 g total amino acids/kg x day(-1) using this product exceeded the combined recommended dietary allowance for aromatic amino acids
  
  
  CONCLUSIONS
  As used in the clinical setting, the phenylalanine and NAT composition of Aminosyn II is sufficient to meet the combined aromatic amino acid needs of adults with normal phenylalanine hydroxylase activity.
authors: Nutrition Support Service, Sir Mortimer B. Davis Jewish General Hospital, Montréal, Québec, Canada. l.hoffer@mcgill.ca
authors: L John
authors: LJ
authors: Hoffer
authors: Khurram
authors: K
authors: Sher
authors: Farhad
authors: F
authors: Saboohi
authors: Paule
authors: P
authors: Bernier
authors: Elizabeth M
authors: EM
authors: MacNamara
authors: David
authors: D
authors: Rinzler
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood / Q000652:urine; D001786:Blood Glucose / Q000378:metabolism; D003404:Creatinine / Q000652:urine; D005260:Female; D006801:Humans; D007263:Infusions, Parenteral; D007668:Kidney / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010288:Parenteral Nutrition; D016896:Treatment Outcome; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000627:therapeutic use* / Q000652:urine; D014508:Urea / Q000652:urine
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D014443:Tyrosine; D014508:Urea; D003404:Creatinine; C025787:N-acetyltyrosine