title: Effect of intravenous infusion of proglumide on ruminal motility in conscious sheep (Ovis aries).
abstract: The effects of intravenous infusion of proglumide on regular ruminal contractions were examined in conscious sheep using doses that inhibit pancreatic exocrine secretion. After a control period of 20 min, proglumide was infused intravenously for 40 min at a dose of 15, 30 or 60 micromol/kg per min and venous blood was collected. The intravenous infusion of proglumide significantly increased the frequency of ruminal contractions at 15 micromol/kg per min without altering the amplitude, while it significantly decreased the frequency and amplitude of ruminal contractions at 30 and 60 micromol/kg per min in a dose-dependent manner. Proglumide did not increase contractile activity of the omasum, abomasum and duodenum or the plasma concentration of immunoreactive cholecystokinin (CCK). Application of proglumide at 1-30 mmol/L inhibited bethanechol-induced contraction in both longitudinal and circular muscle strips of the dorsal sac of the rumen. These results suggest that proglumide at a low dose acts indirectly on the rumen as a CCK receptor antagonist to increase the frequency of contractions, whereas at higher doses it inhibits cholinergic-induced contraction of the ruminal muscles or acts as an agonist to inhibit contractions in sheep. Hence, proglumide at high doses seems unsuitable for research or therapeutic use as a CCK receptor blockade in sheep.
authors.affiliation: Laboratory of Veterinary Physiology, Department of Biosciences, School of Veterinary Medicine, Rakuno Gakuen University, Japan. onaga@rakuno.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Onaga
mesh_terms: D000018:Abomasum / Q000187:drug effects / Q000502:physiology; D000818:Animals; D002766:Cholecystokinin / Q000097:blood; D004386:Duodenum / Q000187:drug effects / Q000502:physiology; D005769:Gastrointestinal Motility / Q000187:drug effects*; D066298:In Vitro Techniques; D007262:Infusions, Intravenous / Q000662:veterinary; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009851:Omasum / Q000187:drug effects / Q000502:physiology; D011377:Proglumide / Q000008:administration & dosage / Q000494:pharmacology*; D011949:Receptors, Cholecystokinin / Q000037:antagonists & inhibitors; D012417:Rumen / Q000187:drug effects* / Q000502:physiology; D012756:Sheep / Q000502:physiology*; D014160:Transducers, Pressure / Q000662:veterinary
chemical_list: D011949:Receptors, Cholecystokinin; D002766:Cholecystokinin; D011377:Proglumide