title: Effect of bethanechol or erythromycin on gastric emptying in horses.
abstract: OBJECTIVE
  To investigate the prokinetic effect of bethanechol and erythromycin in the upper gastrointestinal tract of healthy horses by measuring the gastric emptying (GE) rate of a radioactive meal.
  
  
  METHODS
  4 healthy adult horses.
  
  
  METHODS
  After food was withheld for 12 hours, horses were given 370 MBq of 99mTc-labeled sulfur colloid incorporated into egg albumen and 37 MBq of 111In-labeled diethyltriaminepentaacetic acid in 120 ml of water via nasogastric intubation. Intravenously administered treatments were 0.9% NaCl solution, erythromycin (0.1 or 1.0 mg/kg of body weight), or bethanechol (0.25 mg/kg). All drugs were given in 10 ml of 0.9% NaCl solution. Dual-phase scintigraphic images were obtained by use of a gamma camera. The best-fit function was determined for each study, and the resultant curves were then analyzed by use of least squares nonlinear regression. Two variables, time to 50% emptying of the stomach (T-50) and slope of the emptying curve, were derived from the calculated power exponential equation.
  
  
  CONCLUSIONS
  Treatment had a significant (P < 0.05) overall effect on T-50 of solid-phase GE. The T-50 of bethanechol (30.09 +/- 10.01 minutes), erythromycin at 0.1 mg/kg (59.08 +/- 10.01 minutes), and erythromycin at 1 mg/kg (60.50 +/- 10.01 minutes) were significantly shorter than T-50 after saline administration (89.97 +/- 10.01 minutes). There was a trend (P = 0.09) for the slope of solid-phase GE of bethanechol and erythromycin (0.1 mg/ kg; P = 0.37) to be steeper than that of saline solution. For liquid-phase GE, the T-50 and the slope of bethanechol differed significantly (P < or = 0.05) from those for saline solution.
  
  
  CONCLUSIONS
  Bethanechol and erythromycin significantly increased solid-phase GE in healthy horses and may have value for use as prokinetic agents in certain gastrointestinal tract diseases.
authors.affiliation: Island Whirl Equine Colic Research Laboratory, Department of Large Animal Clinical Sciences, University of Florida, Gainesville 2610-0136, USA.
authors.forename: N C
authors.initials: NC
authors.lastname: Ringger
authors.forename: G D
authors.initials: GD
authors.lastname: Lester
authors.forename: L
authors.initials: L
authors.lastname: Neuwirth
authors.forename: A M
authors.initials: AM
authors.lastname: Merritt
authors.forename: T
authors.initials: T
authors.lastname: Vetro
authors.forename: J
authors.initials: J
authors.lastname: Harrison
mesh_terms: D000818:Animals; D018723:Bethanechol / Q000494:pharmacology*; D004917:Erythromycin / Q000494:pharmacology*; D005746:Gastric Emptying / Q000187:drug effects*; D006736:Horses; D007205:Indium Radioisotopes; D004369:Pentetic Acid; D011877:Radionuclide Imaging; D013270:Stomach / Q000000981:diagnostic imaging; D013671:Technetium Tc 99m Sulfur Colloid
chemical_list: D007205:Indium Radioisotopes; D018723:Bethanechol; D013671:Technetium Tc 99m Sulfur Colloid; D004917:Erythromycin; D004369:Pentetic Acid