Abstract
We studied the effects of amount and source of nonspecific nitrogen (NSN) on the oxidation of leucine and hydroxylation of phenylalanine. In phase 1, seven adult males received for 6 d diets providing indispensable amino acid intakes to meet the 1985 FAO/WHO/UNU (FAO) requirements or our proposed requirement values (MIT). During one diet period with each diet, the NSN of the basal diets (total nitrogen intake: 107 mg N-kg-1·d-1) was increased to a total of 160 mg N·kg-1·d-1. On the morning of day 7, an 8-h constant intravenous tracer-infusion protocol (3-h fast; 5-h fed state) was conducted with L-[1-13C]leucine, L-[ring-2H5]phenylalanine, and L-[3,3,2H2]-tyrosine as tracers. In phase 2, six subjects were given three diets for 6 d, supplying 107 mg N·kg-1·d-1; NSN was a mixture of dispensable amino acids in which glutamine accounted for 0%, 12.5%, and 100% of total NSN. Leucine oxidation and phenylalanine hydroxylation rates and whole-body leucine and phenylalanine balances were unaffected by addition of supplemental NSN to the diets in phase 1 or by amino acid source of NSN in phase 2. Leucine and phenylalanine balances were lower (P < 0.05) for FAO compared with MIT diets.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1347-1355 |
| Number of pages | 9 |
| Journal | American Journal of Clinical Nutrition |
| Volume | 59 |
| Issue number | 6 |
| State | Published - Jun 1994 |
| Externally published | Yes |
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Keywords
- Amino acids
- Kinetics
- Leucine
- Phenylalanine
- Requirements
ASJC Scopus subject areas
- Food Science
- Medicine (miscellaneous)
Cite this
Source and amount of dietary nonspecific nitrogen in relation to whole-body leucine, phenylalanine, and tyrosine kinetics in young men. / Hiramatsu, Takeyuki; Cortiella, Joaquin; Marchini, J. Sérgio; Chapman, Thomas E.; Young, Vernon R.
In: American Journal of Clinical Nutrition, Vol. 59, No. 6, 06.1994, p. 1347-1355.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Source and amount of dietary nonspecific nitrogen in relation to whole-body leucine, phenylalanine, and tyrosine kinetics in young men
AU - Hiramatsu, Takeyuki
AU - Cortiella, Joaquin
AU - Marchini, J. Sérgio
AU - Chapman, Thomas E.
AU - Young, Vernon R.
PY - 1994/6
Y1 - 1994/6
N2 - We studied the effects of amount and source of nonspecific nitrogen (NSN) on the oxidation of leucine and hydroxylation of phenylalanine. In phase 1, seven adult males received for 6 d diets providing indispensable amino acid intakes to meet the 1985 FAO/WHO/UNU (FAO) requirements or our proposed requirement values (MIT). During one diet period with each diet, the NSN of the basal diets (total nitrogen intake: 107 mg N-kg-1·d-1) was increased to a total of 160 mg N·kg-1·d-1. On the morning of day 7, an 8-h constant intravenous tracer-infusion protocol (3-h fast; 5-h fed state) was conducted with L-[1-13C]leucine, L-[ring-2H5]phenylalanine, and L-[3,3,2H2]-tyrosine as tracers. In phase 2, six subjects were given three diets for 6 d, supplying 107 mg N·kg-1·d-1; NSN was a mixture of dispensable amino acids in which glutamine accounted for 0%, 12.5%, and 100% of total NSN. Leucine oxidation and phenylalanine hydroxylation rates and whole-body leucine and phenylalanine balances were unaffected by addition of supplemental NSN to the diets in phase 1 or by amino acid source of NSN in phase 2. Leucine and phenylalanine balances were lower (P < 0.05) for FAO compared with MIT diets.
AB - We studied the effects of amount and source of nonspecific nitrogen (NSN) on the oxidation of leucine and hydroxylation of phenylalanine. In phase 1, seven adult males received for 6 d diets providing indispensable amino acid intakes to meet the 1985 FAO/WHO/UNU (FAO) requirements or our proposed requirement values (MIT). During one diet period with each diet, the NSN of the basal diets (total nitrogen intake: 107 mg N-kg-1·d-1) was increased to a total of 160 mg N·kg-1·d-1. On the morning of day 7, an 8-h constant intravenous tracer-infusion protocol (3-h fast; 5-h fed state) was conducted with L-[1-13C]leucine, L-[ring-2H5]phenylalanine, and L-[3,3,2H2]-tyrosine as tracers. In phase 2, six subjects were given three diets for 6 d, supplying 107 mg N·kg-1·d-1; NSN was a mixture of dispensable amino acids in which glutamine accounted for 0%, 12.5%, and 100% of total NSN. Leucine oxidation and phenylalanine hydroxylation rates and whole-body leucine and phenylalanine balances were unaffected by addition of supplemental NSN to the diets in phase 1 or by amino acid source of NSN in phase 2. Leucine and phenylalanine balances were lower (P < 0.05) for FAO compared with MIT diets.
KW - Amino acids
KW - Kinetics
KW - Leucine
KW - Phenylalanine
KW - Requirements
UR - http://www.scopus.com/inward/record.url?scp=0028360451&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0028360451&partnerID=8YFLogxK
M3 - Article
C2 - 8198059
AN - SCOPUS:0028360451
VL - 59
SP - 1347
EP - 1355
JO - American Journal of Clinical Nutrition
JF - American Journal of Clinical Nutrition
SN - 0002-9165
IS - 6
ER -