title: Effects of acute endotoxemia on serum somatotropin and insulin-like growth factor I concentrations in prepubertal gilts.
abstract: OBJECTIVE
  To evaluate effects of endotoxemia on serum somatotropin (ST) and insulin-like growth factor I (IGF-I) concentrations in finishing pigs.
  
  
  METHODS
  Eight female pigs (98 +/- 2 kg) randomly assigned to IV administration (time 0) of saline solution (n = 4) or Escherichia coli lipopolysaccharide (LPS; 5 micrograms/kg of body weight; n = 4).
  
  
  METHODS
  Serum ST concentration was determined in serum samples obtained at 20-minute intervals for 6 hours after treatment. Serum IGF-I concentration was determined in samples collected at 1-hour intervals for 6 hours and at 12, 15, 18, 24, 48, 72, and 96 hours after treatment.
  
  
  RESULTS
  One distinct pulse of ST (peak 10.5 +/- 0.5 ng/ml) was observed at 40 minutes in each pig after administration of LPS. Control pigs had 2.25 +/- 0.48 ST pulses during the 6 hours of frequent sample collection; however, magnitude of the ST pulses was similar between gilts given LPS and control gilts. A temporal association between ST pulses and saline administration was not evident. Serum IGF-I concentration was similar between gilts of the LPS and control groups prior to treatment. The IGF-I concentration was similar between gilts of the LPS and control groups prior to treatment. The IGF-I concentration was lower (P < 0.01) in gilts of the LPS group (44 +/- 5 ng/ml) than in gilts of the control group (157 +/- 4 ng/ml) at 24 hours. The difference in IGF-I concentrations between groups was evident for 96 hours.
  
  
  CONCLUSIONS
  Immediate release of ST was attributed to stress associated with acute endotoxemia and stimulation of the pituitary gland; immune stimulation by LPS may have contributed to the changes in IGF-I concentration. Because feed consumption was similar between the 2 groups of pigs, suppression of IGF-I concentration for 96 hours after administration of LPS was attributable to factors in addition to transient feed restriction. Thus, acute endotoxemia altered the positive association between ST and IGF-I, and provided evidence for a potential mechanism of impaired growth in endotoxemic animals.
authors.affiliation: Department of Food Animal & Equine Medicine, North Carolina State University, Raleigh 27606, USA.
authors.forename: W
authors.initials: W
authors.lastname: Hevener
authors.forename: G W
authors.initials: GW
authors.lastname: Almond
authors.forename: J D
authors.initials: JD
authors.lastname: Armstrong
authors.forename: R G
authors.initials: RG
authors.lastname: Richards
mesh_terms: D000818:Animals; D019446:Endotoxemia / Q000097:blood*; D004926:Escherichia coli; D005260:Female; D013006:Growth Hormone / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis / Q000378:metabolism*; D007700:Kinetics; D008070:Lipopolysaccharides; D012741:Sexual Maturation; D013552:Swine; D013997:Time Factors
chemical_list: D008070:Lipopolysaccharides; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone