title: Evaluation of a modified acetaminophen absorption test to estimate the abomasal emptying rate in Holstein-Friesian heifers.
abstract: OBJECTIVE
  To assess the suitability of the modified acetaminophen absorption test for evaluation of abomasal emptying rate in ruminating cattle.
  
  
  METHODS
  7 Holstein-Friesian heifers.
  
  
  METHODS
  In a crossover study design, heifers consecutively underwent an IV infusion of 1 L of saline (0.9% NaCl) solution (control treatment), 1 L of saline solution containing metoclopramide (0.1 mg/kg), and 1 L of saline solution containing atropine (0.1 mg/kg), with an interval of 15 days between treatments. Immediately after each treatment, acetaminophen diluted in ethanol (50 mg/kg) was infused transcutaneously into the abomasum. Blood samples were obtained repeatedly for measurement of plasma acetaminophen concentration, and pharmacokinetic data were obtained.
  
  
  RESULTS
  Maximum plasma acetaminophen concentration was significantly lower after atropine treatment than after control or metoclopramide treatment, whereas no difference was identified between control and metoclopramide treatments. The interval to maximum plasma acetaminophen concentration was significantly longer in atropine-treated versus metoclopramide-treated heifers. The interval to maximum acetaminophen concentration obtained from a pharmacokinetic model was significantly longer for atropine than for control and metoclopramide treatment. Similarly, areas under the plasma acetaminophen concentration-time curves for the first 60, 90, 120, and 240 minutes after administration were significantly lower for atropine versus metoclopramide or control treatment, whereas differences between metoclopramide and control treatments were not identified.
  
  
  CONCLUSIONS
  The modified acetaminophen absorption test was a practical, minimally invasive, and reliable method to assess abomasal emptying in cattle. Metoclopramide administered at a dose of 0.1 mg/kg did not increase the abomasal emptying rate.
authors: Department of Clinical Sciences, School of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, 9177948977, Iran.
authors: Abdullah
authors: A
authors: Ehsani-Kheradgerdi
authors: Kamran
authors: K
authors: Sharifi
authors: Mehrdad
authors: M
authors: Mohri
authors: Walter
authors: W
authors: Grünberg
mesh_terms: D000018:Abomasum / Q000187:drug effects* / Q000502:physiology; D000042:Absorption; D000082:Acetaminophen / Q000097:blood / Q000493:pharmacokinetics*; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000097:blood / Q000493:pharmacokinetics*; D000932:Antiemetics / Q000494:pharmacology; D019540:Area Under Curve; D001285:Atropine / Q000494:pharmacology; D002417:Cattle / Q000502:physiology; D018592:Cross-Over Studies; D005260:Female; D005746:Gastric Emptying; D007262:Infusions, Intravenous / Q000662:veterinary; D055104:Infusions, Subcutaneous / Q000662:veterinary; D007408:Intestinal Absorption; D008787:Metoclopramide / Q000494:pharmacology; D010276:Parasympatholytics / Q000494:pharmacology; D014730:Veterinary Medicine / Q000379:methods*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000932:Antiemetics; D010276:Parasympatholytics; D000082:Acetaminophen; D001285:Atropine; D008787:Metoclopramide