GABA A receptor mediated neurogenic inhibition of motility in the small intestine of urethane-anaesthetized rats.
Intravenous GABA (0.1-3 mg/kg) induced transient relaxation of the duodenum in urethane anaesthetized rats. The effect of GABA was mimicked by homotaurine and antagonized by bicuculline, suggesting the involvement of GABA A receptors in this type of response. Duodenal relaxation induced by GABA was unaffected by i.v. hexamethonium, phentolamine propranolol or 6-hydroxydopamine but was prevented in preparations pretreated with topical tetrodotoxin thus indicating its neurogenic origin. The ability of GABA to induce neurogenic relaxation decreased rapidly when increasing the distance from the duodenum while relaxations induced by DMPP or noradrenaline were observed throughout the whole rat small intestine.
D000758:Anesthesia; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D005769:Gastrointestinal Motility / Q000187:drug effects*; D006584:Hexamethonium Compounds / Q000494:pharmacology; D066298:In Vitro Techniques; D007421:Intestine, Small / Q000187:drug effects*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D009638:Norepinephrine / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011963:Receptors, GABA-A / Q000187:drug effects / Q000502:physiology*; D013654:Taurine / Q000031:analogs & derivatives / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology; D014520:Urethane
D006584:Hexamethonium Compounds; D011963:Receptors, GABA-A; D013654:Taurine; D014520:Urethane; D013779:Tetrodotoxin; C001355:tramiprosate; D011433:Propranolol; D009638:Norepinephrine; D001640:Bicuculline; D010646:Phentolamine