Ketamine may modify intestinal motility by acting at GABAA-receptor complex; an in vitro study on the guinea pig intestine.
In the present study the effect of ketamine, a dissociative anaesthetic, on the GABA- and on the specific GABAA-agonist muscimol-induced responses of the isolated guinea pig ileum was investigated. GABA as well as muscimol produce a concentration-dependent contractile effect on the duodenum, jejunum and ileum. The sensitivity of the intestinal parts to both the above substances increases from the duodenum to the ileum. Ketamine produces a non-competitive inhibition of the GABA- and muscimol-induced contractions of the ileum, while it does not influence the ileal cholinergic contractions induced by exogenous acetylcholine. These results suggest that ketamine may modify intestinal motility through its antagonistic action at the GABAA-receptor complex.
Kounenis
G
G
Department of Pharmacology, Faculty of Veterinary Medicine, Aristotelian University, Thessaloniki, Greece.
Koutsoviti-Papadopoulou
M
M
Elezoglou
V
V
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D005769:Gastrointestinal Motility / Q000187:drug effects*; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D007649:Ketamine / Q000494:pharmacology*; D008297:Male; D009118:Muscimol / Q000494:pharmacology; D018079:Receptors, GABA / Q000187:drug effects*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D018079:Receptors, GABA; D009118:Muscimol; D005680:gamma-Aminobutyric Acid; D007649:Ketamine; D000109:Acetylcholine