title: Long-term oxandrolone treatment increases muscle protein net deposition via improving amino acid utilization in pediatric patients 6 months after burn injury.
abstract: BACKGROUND
  We recently showed that mechanisms of protein turnover in skeletal muscle are unresponsive to amino acid (AA) infusion in severely burned pediatric patients at 6 months postinjury. In the current study, we evaluated whether oxandrolone treatment affects mechanisms of protein turnover in skeletal muscle and whole-body protein breakdown in pediatric burn patients 6 months postinjury.
  
  
  METHODS
  At the time of admission, patients were randomized to control or oxandrolone treatments. The treatment regimens were continued until 6 months postinjury, at which time patients (n = 26) underwent study with a stable isotope tracer infusion to measure muscle and whole-body protein turnover.
  
  
  RESULTS
  Protein kinetics in leg muscle were expressed in nmol/min per 100 mL leg volume (mean ± SE). During AA infusion, rates of protein synthesis in leg muscle were increased (P < .05) in both groups (basal vs AA: control, 51 ± 8 vs 86 ± 21; oxandrolone, 56 ± 7 vs 96 ± 12). In the control group, there was also a simultaneous increase in breakdown (basal vs AA: 65 ± 10 vs 89 ± 25), which resulted in no change in the net balance of leg muscle protein (basal vs AA: -15 ± 4 vs -2 ± 10). In the oxandrolone group, protein breakdown did not change (basal vs AA: 80 ± 12 vs 77 ± 9), leading to increased net balance (basal vs AA: -24 ± 7 vs 19 ± 7; P < .05). Protein breakdown at the whole-body level was not different between the groups.
  
  
  CONCLUSIONS
  Long-term oxandrolone treatment increased net deposition of leg muscle protein during AA infusion by attenuating protein breakdown, but did not affect whole-body protein breakdown.
authors.affiliation: Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555-1220, USA.
authors.forename: Demidmaa
authors.initials: D
authors.lastname: Tuvdendorj
authors.forename: David L
authors.initials: DL
authors.lastname: Chinkes
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Zhang
authors.forename: Oscar E
authors.initials: OE
authors.lastname: Suman
authors.forename: Asle
authors.initials: A
authors.lastname: Aarsland
authors.forename: Arny
authors.initials: A
authors.lastname: Ferrando
authors.forename: Gabriela A
authors.initials: GA
authors.lastname: Kulp
authors.forename: Marc G
authors.initials: MG
authors.lastname: Jeschke
authors.forename: Robert R
authors.initials: RR
authors.lastname: Wolfe
authors.forename: David N
authors.initials: DN
authors.lastname: Herndon
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D045930:Anabolic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002056:Burns / Q000188:drug therapy / Q000378:metabolism*; D002648:Child; D005500:Follow-Up Studies; D006801:Humans; D007866:Leg; D008137:Longitudinal Studies; D009124:Muscle Proteins / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism; D010074:Oxandrolone / Q000494:pharmacology* / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D000596:Amino Acids; D045930:Anabolic Agents; D009124:Muscle Proteins; D010074:Oxandrolone