title: Acute phase modulation of systemic insulin-like growth factor-1 and its binding proteins after major burn injuries.
abstract: OBJECTIVE
  To provide a detailed, sequential analysis of insulin-like growth factor-1 and its binding proteins in adults during the acute phase after a major burn injury.
  
  
  METHODS
  Descriptive, repeated measurements for quantitation and characterization of insulin-like growth factor-1 and its binding proteins in adult burn survivors.
  
  
  METHODS
  Burn center in a university hospital.
  
  
  METHODS
  A total of 17 severely burned (>15% total body-surface area burned) adult patients.
  
  
  METHODS
  Venous blood was collected twice a day for 10 days and centrifuged, and the sera were stored at -80 degrees C until analysis. A series of 340 serum samples were analyzed by radioimmunoassay to determine the circulating concentration of insulin-like growth factor-1 and its major binding proteins (insulin-like growth factor-binding protein), by Western ligand blotting. To better understand the changes seen in systemic insulin-like growth factor-binding protein-3 levels by Western ligand blotting, a proteolysis assay was performed.
  
  
  RESULTS
  Insulin-like growth factor-1 levels were reduced from day 0 and correlated with insulin-like growth factor-binding protein-1 and -2 (p <.01), but not insulin-like growth factor-binding protein-3 and -4. Insulin-like growth factor-binding protein-3 was decreased relative to normal on day 0, declined further until day 3, and began recovering by day 6, but returned to only 35% of normal by day 10. Insulin-like growth factor-binding protein-1 and -2 were increased relative to normal and remained increased throughout the 10-day period. Insulin-like growth factor-binding protein-4 concentrations, however, were similar to normal at day 1 but gradually increased over time. Burn serum incubated with recombinant human glycosylated iodine-125 insulin-like growth factor-binding protein-3 did not demonstrate any proteolysis, although proteolysis of nonglycosylated iodine-125 insulin-like growth factor-binding protein-3 reached levels of approximately 40%.
  
  
  CONCLUSIONS
  Insulin-like growth factor-binding protein-3 proteolysis does not seem to be the mechanism by which systemic insulin-like growth factor-1 levels are reduced in major burn survivors. In vitro proteolysis of recombinant human glycosylated and nonglycosylated iodine-125 insulin-like growth factor-binding protein-3 does not reflect the in vivo situation in major burn survivors.
authors.affiliation: McGill University, Montreal, Quebec, Canada.
authors.forename: Bernadette
authors.initials: B
authors.lastname: Nedelec
authors.forename: Ana
authors.initials: A
authors.lastname: de Oliveira
authors.forename: Dominique R
authors.initials: DR
authors.lastname: Garrel
mesh_terms: D000210:Acute-Phase Reaction / Q000097:blood*; D000293:Adolescent; D000328:Adult; D000368:Aged; D002056:Burns / Q000097:blood / Q000276:immunology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D018969:Insulin-Like Growth Factor Binding Proteins / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis
chemical_list: D018972:Insulin-Like Growth Factor Binding Protein 3; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I