title: Quantification of protein metabolism in vivo for skin, wound, and muscle in severe burn patients.
abstract: BACKGROUND
  In response to injury, muscle catabolism can be extensive, and in theory, the wound consumes amino acids to support healing. The purpose of this study is to assess a technique by which in vivo protein kinetics of muscle, wound, and normal skin can be quantified in burn-injured patients.
  
  
  METHODS
  Study protocol consisting of infusion of d5 phenylalanine; biopsies of skeletal muscle, skin, and donor-site wound on the leg; quantification of blood flow to total leg, wound, and skin; and sequential blood sampling from the femoral artery and vein. Five-compartment modeling was used to quantify the rates of protein synthesis, breakdown, and phenylalanine transport between muscle, wound, and skin.
  
  
  RESULTS
  The study results demonstrated a net release of phenylalanine from muscle yet a net consumption of phenylalanine by the wound. Compared with skin, the wound had a substantially increased rate of protein synthesis and a reduced rate of protein breakdown (p < .01). Transport rates into and out of muscle were significantly higher than those for wound (p < .01).
  
  
  CONCLUSIONS
  This novel methodology enables in vivo quantification of the integrated response of muscle, wound, and skin protein/amino acid metabolism and confirms the long-held theory of a net catabolism of muscle and a net anabolism of wound protein in patients after injury. This methodology can be used to assess the metabolic impact of such measures as nutrition, pharmacologic agents, and surgical procedures.
authors.affiliation: Department of Surgery, The University of Texas Medical Branch, Galveston, Texas 77555-1172, USA. dcgore@utmb.edu
authors.forename: Dennis C
authors.initials: DC
authors.lastname: Gore
authors.forename: David L
authors.initials: DL
authors.lastname: Chinkes
authors.forename: Steven E
authors.initials: SE
authors.lastname: Wolf
authors.forename: Arthur P
authors.initials: AP
authors.lastname: Sanford
authors.forename: David N
authors.initials: DN
authors.lastname: Herndon
authors.forename: Robert R
authors.initials: RR
authors.lastname: Wolfe
mesh_terms: D000328:Adult; D001481:Basal Metabolism / Q000502:physiology; D002056:Burns / Q000378:metabolism* / Q000503:physiopathology; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D007866:Leg / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D009124:Muscle Proteins / Q000096:biosynthesis / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000378:metabolism*; D010649:Phenylalanine / Q000378:metabolism; D012039:Regional Blood Flow; D012867:Skin / Q000098:blood supply / Q000378:metabolism*; D013997:Time Factors; D014945:Wound Healing / Q000502:physiology; D014947:Wounds and Injuries / Q000378:metabolism*
chemical_list: D009124:Muscle Proteins; D010649:Phenylalanine