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Amino Acids

, Volume 12, Issue 2, pp 119–137 | Cite as

Portal-drained viscera and hepatic fluxes of branched-chain amino acids do not account for differences in circulating branched-chain amino acids in rats fed arginine-deficient diets

  • W. J. Hartman
  • R. L. Prior
Full Papers

Summary

Concentrations and fluxes of amino acids across the portal-drained viscera (PDV) and liver were assessed in rats fed a meal of one of three arginine-deficient diets containing either alanine or the arginine precursors, ornithine or citrulline. A previous report included findings of seven arginine-related amino acids and indicated that only the citrulline-containing diet protected blood arginine concentrations. In the present report we extend these findings and note that the concentrations and fluxes of the non-arginine-related amino acids showed remarkable consistency across diet groups. However, total branched-chain amino acid (BCAA) concentrations of arterial blood were higher in rats fed the - Arg/+ Ala and the - Arg/+ Orn diets than in rats fed the control (+ Arg) diet. The elevated BCAA correlated with higher circulating concentrations of other essential amino acids but were inversely correlated with arginine concentrations. PDV and hepatic fluxes of BCAA were not different across diet groups, indicating that amino acid absorption and hepatic utilization of BCAA were generally comparable across diet groups. Hepatic concentrations of 14 of 22 measured amino acids, including total BCAA, were correlated with their arterial concentrations. The circulating concentrations and net PDV and hepatic fluxes of rats fed the control diet were comparable to our previous observations in fed rats and illustrate the role of the liver in utilization of diet-derived essential amino acids.

Keywords

Essential amino acids Fed state Interorgan flux Rats Arginine deficiency 

Abbreviations

PDV

portal-drained viscera

BCAA

branched-chain amino acids

SSA

5-sulfosalicylic acid

PBF

portal blood flow

HBF

hepatic blood flow

SELSM

pooled standard errors of least squares means

TAA

total amino acids

NEAA

nonessential amino acids

EAA

essential amino acids

LNAA

large neutral amino acids

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Copyright information

© Springer-Verlag 1997

Authors and Affiliations

  • W. J. Hartman
    • 1
  • R. L. Prior
    • 1
  1. 1.U.S. Department of Agriculture, Agricultural Research ServiceJean Mayer Human Nutrition Research Center on Aging at Tufts UniversityBostonUSA

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