title: Effects of an intravenous endotoxin challenge on glucose and insulin dynamics in horses.
abstract: OBJECTIVE
  To evaluate the effects of endotoxin administered IV on glucose and insulin dynamics in horses.
  
  
  METHODS
  16 healthy adult mares.
  
  
  METHODS
  Each week of a 2-week randomized crossover study, each horse received an IV injection (duration, 30 minutes) of Escherichia coli O55:B5 lipopolysaccharide (LPS) in 60 mL of sterile saline (0.9% NaCl) solution (20 ng/kg) or sterile saline solution alone (control treatment). Frequently sampled IV glucose tolerance test procedures were performed at 24 hours before (baseline) and 24 and 48 hours after injection; glucose and insulin dynamics were assessed via minimal model analysis.
  
  
  RESULTS
  13 of 16 horses had a clinical response to LPS, which was characterized by mild colic and leukopenia. Before treatment, mean +/- SD insulin sensitivity was 2.9 +/- 1.9 x 10(4) L x min(1) x mU(1); this significantly decreased to 0.9 +/- 0.9 x 10(4) L x min(1) x mU(1) 24 hours after treatment (69% reduction) and was 1.5 +/- 0.9 x 10(4) L x min(1) x mU(1) 48 hours after treatment. At baseline, mean +/- SD acute insulin response to glucose was 520 +/- 196 mU x min x L(1); this significantly increased to 938 +/- 620 mU x min x L(1) (80% increase) and 755 +/- 400 mU x min x L(1) (45% increase) at 24 and 48 hours after LPS treatment, respectively.
  
  
  CONCLUSIONS
  Compared with baseline values, insulin sensitivity was decreased for 24 hours after IV injection of LPS, and affected horses had a compensatory pancreatic response. These disturbances in glucose and insulin dynamics may contribute to development of laminitis in horses.
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996, USA.
authors.forename: Ferenc
authors.initials: F
authors.lastname: Tóth
authors.forename: Nicholas
authors.initials: N
authors.lastname: Frank
authors.forename: Sarah B
authors.initials: SB
authors.lastname: Elliott
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Geor
authors.forename: Raymond C
authors.initials: RC
authors.lastname: Boston
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000187:drug effects* / Q000378:metabolism; D018592:Cross-Over Studies; D005260:Female; D006736:Horses / Q000097:blood / Q000378:metabolism*; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000009:adverse effects*
chemical_list: D001786:Blood Glucose; D007328:Insulin; D008070:Lipopolysaccharides