title: Effects of dexamethasone-21-isonicotinate on peripheral insulin action in dairy cows 5 days after surgical correction of abomasal displacement.
abstract: BACKGROUND
  Dexamethasone frequently is used for treatment of ketosis in dairy cows, but its effects are not fully understood.
  
  
  OBJECTIVE
  Dexamethasone treatment affects whole body insulin sensitivity.
  
  
  METHODS
  Twelve German Holstein cows, 2-4 weeks postpartum, 5 days after omentopexy to correct left abomasal displacement.
  
  
  METHODS
  Randomized, blinded, case-control study. Treatment with dexamethasone-21-isonicotinate (DG; 40 μg/kg IM; n = 6) or saline (control group [CG], 15 mL IM, n = 6) on day 0 (d0). Blood samples were obtained before (d0) and after treatment (d1 and d2), and analyzed for glucose, insulin, and nonesterified fatty acid (NEFA) concentrations. Hepatic triglycerides (TAG) were measured in liver samples taken on d0 and d2. Five consecutive hyperinsulinemic-euglycemic clamps (HEC-I-V; insulin dosages: 0.1, 0.5, 2, 5, 10 mU/kg/min, respectively) were performed on d1 and steady state glucose infusion rate (SSGIR), insulin concentration (SSIC), insulin sensitivity index (ISI = SSGIR/SSIC), and plasma NEFA concentration (SSNEFA) were assessed.
  
  
  RESULTS
  Compared with CG-cows, DG-cows on d1 had higher plasma glucose (P = .004) and insulin (P < .001) concentrations, decreased SSGIR (HEC-II, P = .002; HEC-IV, P = .033), ISI (HEC-I, P < .015; HEC-II, P = .004), and insulin-stimulated decrease in SSNEFA (HEC-II, P = .006; HEC-III, P = .01; HEC-IV, P = .003; HEC-V, P = .011). Decrease in hepatic TAG content in DG-cows was higher compared with CG-cows (P < .001).
  
  
  CONCLUSIONS
  Dexamethasone decreases whole body insulin sensitivity and affects glucose and lipid metabolism in early lactating dairy cows.
authors.affiliation: Clinic for Cattle, University of Veterinary Medicine Hannover, Hannover, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Kusenda
authors.forename: M
authors.initials: M
authors.lastname: Kaske
authors.forename: M
authors.initials: M
authors.lastname: Piechotta
authors.forename: L
authors.initials: L
authors.lastname: Locher
authors.forename: A
authors.initials: A
authors.lastname: Starke
authors.forename: K
authors.initials: K
authors.lastname: Huber
authors.forename: J
authors.initials: J
authors.lastname: Rehage
mesh_terms: D000018:Abomasum / Q000601:surgery*; D000818:Animals; D001786:Blood Glucose; D016022:Case-Control Studies; D002417:Cattle; D002418:Cattle Diseases / Q000601:surgery*; D003612:Dairying; D003908:Dexamethasone Isonicotinate / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D007328:Insulin / Q000097:blood*; D013272:Stomach Diseases / Q000601:surgery / Q000662:veterinary*
chemical_list: D001786:Blood Glucose; D007328:Insulin; D003908:Dexamethasone Isonicotinate