Alpha 2-adrenoceptor antagonist activity may account for the effects of buspirone in an anticonflict test in the rat.
The anxiolytic effects of buspirone, its metabolite, 1-(2-pyrimidyl)piperazine (1-PP) and several alpha 2-adrenoceptor antagonists have been compared in an anticonflict (shock-induced suppression of drinking) paradigm in rats. Idazoxan, WY 26392 and yohimbine had anticonflict effects comparable to those of buspirone and 1-PP, and enhanced the release of suppressed responding induced by buspirone. The response to buspirone was antagonised by the alpha 2-adrenoceptor agonist clonidine. In tests of clonidine-induced mydriasis, the antagonist potencies of buspirone, 1-PP, idazoxan, WY 26392 and yohimbine corresponded closely to the doses of the compounds active in the anticonflict test. Clonidine-induced hypolocomotion was also antagonised by 1-PP, although this response was potentiated by buspirone. The results suggest that the anticonflict effects of buspirone involve an alpha 2-adrenoceptor mechanism.
Gower
A J
AJ
Merrell Dow Research Centre, Strasbourg, France.
Tricklebank
M D
MD
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D002065:Buspirone / Q000494:pharmacology*; D003220:Conflict, Psychological; D004305:Dose-Response Relationship, Drug; D004327:Drinking Behavior / Q000187:drug effects; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009184:Mydriatics; D051381:Rats; D011919:Rats, Inbred Strains; D012054:Reinforcement, Psychology
D000317:Adrenergic alpha-Antagonists; D009184:Mydriatics; D002065:Buspirone