Article date: 1992/9/22
PubMed ID: 1425988
Journal name: European journal of pharmacology (ISSN: 0014-2999)
The effect of tetrahydroisoxazolo-pyridin-3-ol (THIP) and muscimol on gastrointestinal transit and a possible mechanism for this effect were studied using the charcoal meal test in mice. These agents inhibited transit dose relatedly. The inhibitory effect was completely reversed by yohimbine and phentolamine. A minor degree of antagonism by bicuculline was observed. There were an additive response in morphine-pretreated animals and partial antagonism in naloxone-pretreated animals. Propranolol failed to modify the inhibitory effect. The findings suggest a predominantly alpha 2-receptor-mediated inhibitory effect on gastrointestinal transit for THIP and muscimol which possibly also utilizes opioid pathways. However, it appears that beta-adrenergic and GABAergic systems might not contribute to this effect.
Author List: Ramaswamy S, Srinivasan D, Bapna J S
Publication Types: Journal Article
Substances mentioned in the article: Isoxazoles; Muscimol; Yohimbine; Propranolol; gaboxadol; Bicuculline; Phentolamine;
Mesh terms: Animals; Bicuculline/pharmacology; Dose-Response Relationship, Drug; Drug Interactions; Gastrointestinal Transit/drug effects; Isoxazoles/antagonists & inhibitors; Male; Mice; Muscimol/antagonists & inhibitors; Phentolamine/pharmacology; Propranolol/pharmacology; Yohimbine/pharmacology;