The effects of medetomidine and xylazine on gastrointestinal motility and gastrin release in the dog.
The effect of medetomidine, a potent and highly selective alpha2-adrenoceptor agonist, on the motility of the gastric antrum, duodenum, mid-jejunum and ileum was investigated in ten dogs. Its effect on the release of gastrin was also determined. Administration of medetomidine intramuscularly (i.m.) at a dose of 40 microg/kg inhibited the motility of the gastric antrum, duodenum, mid-jejunum and ileum significantly, in comparison to administration of xylazine intramuscularly at a dose of 2.0 mg/kg. The release of gastrin was also significantly decreased in dogs receiving medetomidine. It was found to inhibit the motility in the gastric antrum and duodenum longer than in the mid-jejunum and ileum, presumably by acting specifically on alpha2-adrenoceptors, likely at the peripheral level. Medetomidine also inhibited the gastric contraction associated with gastrin secretion.
Nakamura
K
K
Department of Veterinary Surgery, Faculty of Agriculture, Iwate University, Morioka, Japan.
Hara
S
S
Tomizawa
N
N
D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D000818:Animals; D004285:Dogs; D004386:Duodenum / Q000187:drug effects / Q000502:physiology; D005260:Female; D005755:Gastrins / Q000097:blood*; D005769:Gastrointestinal Motility / Q000187:drug effects*; D007082:Ileum / Q000187:drug effects / Q000502:physiology; D007093:Imidazoles / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D007273:Injections, Intramuscular / Q000662:veterinary; D007583:Jejunum / Q000187:drug effects / Q000502:physiology; D008297:Male; D020926:Medetomidine; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D011706:Pyloric Antrum / Q000187:drug effects / Q000502:physiology; D014991:Xylazine / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*
D000316:Adrenergic alpha-Agonists; D005755:Gastrins; D007093:Imidazoles; D014991:Xylazine; D020926:Medetomidine