N-acetyl-L-tyrosine as a tyrosine source in adult parenteral nutrition.
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.
Hoffer
L John
LJ
Nutrition Support Service, Sir Mortimer B. Davis Jewish General Hospital, Montréal, Québec, Canada. l.hoffer@mcgill.ca
Sher
Khurram
K
Saboohi
Farhad
F
Bernier
Paule
P
MacNamara
Elizabeth M
EM
Rinzler
David
D
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
D015415:Biomarkers; D001786:Blood Glucose; D014443:Tyrosine; D014508:Urea; D003404:Creatinine; C025787:N-acetyltyrosine