Inhibition of intestinal motility and reversal of postlaparotomy ileus by selective alpha 2-adrenergic drugs in the rat

Gastroenterology. 1993 Mar;104(3):819-24. doi: 10.1016/0016-5085(93)91018-d.


Background: The effects of selective alpha-agonist medetomidine and alpha 2-antagonist atipamezole on gastrointestinal motility were studied.

Methods: The passage of intragastrically administered Evans blue in the small bowel of unanesthetized rats was followed, and the stomachs were weighted after killing the rats.

Results: Subcutaneous medetomidine, 0.01-0.1 mg/kg, was found to delay small intestinal transit but not gastric emptying, with a maximal effect seen at 0.03 mg/kg. Atipamezole fully reversed the effect of 0.1 mg/kg of medetomidine with a dose of 2.5 mg/kg. Atipamezole alone did not affect small intestinal transit. Subcutaneous morphine, 6 mg/kg, delayed gastric emptying and small intestinal transit, whereas intraperitoneal morphine only delayed gastric emptying. Subcutaneous atipamezole, 0.06 mg/kg, was partially able to reverse the delayed intestinal transit but did not inhibit morphine-induced gastric retention. Subcutaneous atipamezole, 0.06 mg/kg, reversed laparotomy-induced ileus completely.

Conclusions: Atipamezole may provide a useful treatment for postlaparotomy ileus.

MeSH terms

  • Adrenergic alpha-Agonists / pharmacology*
  • Adrenergic alpha-Antagonists / pharmacology*
  • Analysis of Variance
  • Animals
  • Dose-Response Relationship, Drug
  • Gastric Emptying / drug effects
  • Gastrointestinal Motility / drug effects*
  • Imidazoles / pharmacology*
  • Imidazoles / therapeutic use
  • Intestinal Obstruction / drug therapy*
  • Intestinal Obstruction / etiology
  • Laparotomy / adverse effects
  • Male
  • Medetomidine
  • Morphine / pharmacology
  • Rats
  • Rats, Wistar
  • Receptors, Adrenergic, alpha / drug effects
  • Receptors, Adrenergic, alpha / physiology


  • Adrenergic alpha-Agonists
  • Adrenergic alpha-Antagonists
  • Imidazoles
  • Receptors, Adrenergic, alpha
  • atipamezole
  • Morphine
  • Medetomidine