title: Relative influence of glucose and insulin on peripheral amino acid metabolism in severely burned patients.
abstract: BACKGROUND
  Protein catabolism and glucose intolerance are prominent in critically injured patients. The objective of this study was to assess if glucose or insulin availability influences the extent of protein catabolism in hypermetabolic patients.
  
  
  METHODS
  Amino acid net balance from the leg was quantitated in 6 severe burn victims. Furthermore, whole body and leg protein kinetics were assessed with 2H5 phenylalanine and 15N alanine. Measurements were obtained after a 9-hour fast, during an IV glucose infusion (30 micromol/kg per minute), and during a hyperinsulinemic (500 mIU/kg per minute) euglycemic clamp.
  
  
  RESULTS
  Compared with fasting values, the administration of glucose resulted in a significantly increased efflux of amino acids from the leg. In contrast, insulin administration significantly decreased the cumulative net efflux of amino acids. During hyperinsulinemia, isotopic measurements demonstrated a significant decrease in alanine appearance and an increase in phenylalanine disappearance into the leg.
  
  
  CONCLUSIONS
  These findings demonstrate that in critically injured patients, acute hyperglycemia increases muscle catabolism despite an endogenous insulin response. In contrast, exogenous insulin given in sufficient amount impedes muscle protein loss. The mechanism for this anabolic effect of insulin may vary between different amino acids.
authors.affiliation: dcgore@utmb.edu
authors.forename: Dennis C
authors.initials: DC
authors.lastname: Gore
authors.forename: Steven E
authors.initials: SE
authors.lastname: Wolf
authors.forename: David N
authors.initials: DN
authors.lastname: Herndon
authors.forename: Robert R
authors.initials: RR
authors.lastname: Wolfe
mesh_terms: D000328:Adult; D000596:Amino Acids / Q000378:metabolism* / Q000493:pharmacokinetics; D002056:Burns / Q000150:complications / Q000378:metabolism*; D003903:Deuterium; D005947:Glucose / Q000008:administration & dosage / Q000494:pharmacology*; D015309:Glucose Clamp Technique; D006801:Humans; D006946:Hyperinsulinism / Q000378:metabolism; D007262:Infusions, Intravenous; D007328:Insulin / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D009124:Muscle Proteins / Q000378:metabolism*; D009587:Nitrogen Isotopes
chemical_list: D000596:Amino Acids; D007328:Insulin; D009124:Muscle Proteins; D009587:Nitrogen Isotopes; D003903:Deuterium; D005947:Glucose