title: Inhibition of rumination in sheep by alpha-adrenoreceptor antagonists.
abstract: Rumination activity was recorded in sheep during a period of 3 h. The amount of rumination occurring in 30 min following the intravenous injection of an alpha 1 blocking drug (prazosin, 0.1 mg/kg) and an alpha 2 blocking drug (idazoxan, 0.1 mg/kg) was reduced compared with control days when saline was given. The observation that rumination can be stimulated by a rapid, intravenous dose of adrenalin was confirmed. The induction of rumination by adrenalin was prevented by these alpha-adrenoreceptor antagonists given singly or together at the dose rate mentioned. These findings are discussed in the light of knowledge that normal reticulo-ruminal motility and food intake can be inhibited by stimulation of alpha 2-adrenoreceptors.
mesh_terms: D000317:Adrenergic alpha-Antagonists / Q000502:physiology*; D000818:Animals; D004146:Dioxanes / Q000494:pharmacology; D002149:Energy Intake / Q000187:drug effects; D004837:Epinephrine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D005769:Gastrointestinal Motility / Q000187:drug effects; D019329:Idazoxan; D011224:Prazosin / Q000494:pharmacology; D012417:Rumen / Q000187:drug effects*; D012756:Sheep / Q000502:physiology*
chemical_list: D000317:Adrenergic alpha-Antagonists; D004146:Dioxanes; D011224:Prazosin; D019329:Idazoxan; D004837:Epinephrine