Inhibition of intestinal motility and reversal of postlaparotomy ileus by selective alpha 2-adrenergic drugs in the rat.
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.
Tanila
H
H
Department of Physiology and Anesthesiology, University of Helsinki, Finland.
Kauppila
T
T
Taira
T
T
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005746:Gastric Emptying / Q000187:drug effects; D005769:Gastrointestinal Motility / Q000187:drug effects*; D007093:Imidazoles / Q000494:pharmacology* / Q000627:therapeutic use; D007415:Intestinal Obstruction / Q000188:drug therapy* / Q000209:etiology; D007813:Laparotomy / Q000009:adverse effects; D008297:Male; D020926:Medetomidine; D009020:Morphine / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology
D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D007093:Imidazoles; D011942:Receptors, Adrenergic, alpha; C050701:atipamezole; D009020:Morphine; D020926:Medetomidine