Document Detail

Effect of protein restriction on (15)N transfer from dietary [(15)N]alanine and [(15)N]Spirulina platensis into urea.
MedLine Citation:
PMID:  11440912     Owner:  NLM     Status:  MEDLINE    
Six normal men consumed a mixed test meal while adapted to high (1.5 g. kg(-1) x day(-1)) and low (0.3 g. kg(-1) x day(-1)) protein intakes. They completed this protocol twice: when the test meals included 3 mg/kg of [(15)N]alanine ([(15)N]Ala) and when they included 30 mg/kg of intrinsically labeled [(15)N]Spirulina platensis ([(15)N]SPI). Six subjects with insulin-dependent diabetes mellitus (IDDM) receiving conventional insulin therapy consumed the test meal with added [(15)N]Ala while adapted to their customary high-protein diet. Protein restriction increased serum alanine, glycine, glutamine, and methionine concentrations and reduced those of leucine. Whether the previous diet was high or low in protein, there was a similar increase in serum alanine, methionine, and branched-chain amino acid concentrations after the test meal and a similar pattern of (15)N enrichment in serum amino acids for a given tracer. When [(15)N]Ala was included in the test meal, (15)N appeared rapidly in serum alanine and glutamine, to a minor degree in leucine and isoleucine, and not at all in other circulating amino acids. With [(15)N]SPI, there was a slow appearance of the label in all serum amino acids analyzed. Despite the different serum amino acid labeling, protein restriction reduced the postmeal transfer of dietary (15)N in [(15)N]Ala or [(15)N]SPI into [(15)N]urea by similar amounts (38 and 43%, respectively, not significant). The response of the subjects with IDDM was similar to that of the normal subjects. Information about adaptive reductions in dietary amino acid catabolism obtained by adding [(15)N]Ala to a test meal appears to be equivalent to that obtained using an intrinsically labeled protein tracer.
M J Hamadeh; L J Hoffer
Publication Detail:
Type:  Clinical Trial; Controlled Clinical Trial; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  American journal of physiology. Endocrinology and metabolism     Volume:  281     ISSN:  0193-1849     ISO Abbreviation:  Am. J. Physiol. Endocrinol. Metab.     Publication Date:  2001 Aug 
Date Detail:
Created Date:  2001-07-06     Completed Date:  2001-08-09     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  100901226     Medline TA:  Am J Physiol Endocrinol Metab     Country:  United States    
Other Details:
Languages:  eng     Pagination:  E349-56     Citation Subset:  IM    
Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada H3T 1E2.
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MeSH Terms
Alanine / metabolism*
Aspartic Acid / blood
Bacterial Proteins
Diabetes Mellitus, Type 1 / metabolism*
Diet, Protein-Restricted*
Gas Chromatography-Mass Spectrometry
Glutamine / blood
Glycine / blood
Isoleucine / blood
Leucine / blood
Methionine / blood
Nitrogen Isotopes / analysis,  metabolism*
Postprandial Period / physiology
Urea / metabolism*
Reg. No./Substance:
0/Bacterial Proteins; 0/Nitrogen Isotopes; 56-40-6/Glycine; 56-41-7/Alanine; 56-84-8/Aspartic Acid; 56-85-9/Glutamine; 57-13-6/Urea; 61-90-5/Leucine; 63-68-3/Methionine; 73-32-5/Isoleucine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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