Quantification of protein metabolism in vivo for skin, wound, and muscle in severe burn patients.
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.
Gore
Dennis C
DC
Department of Surgery, The University of Texas Medical Branch, Galveston, Texas 77555-1172, USA. dcgore@utmb.edu
Chinkes
David L
DL
Wolf
Steven E
SE
Sanford
Arthur P
AP
Herndon
David N
DN
Wolfe
Robert R
RR
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*
D009124:Muscle Proteins; D010649:Phenylalanine