title: An imidazodiazepine derivative, Ro 15-1788, behaves as a weak partial agonist in the crossed extensor reflex.
abstract: The antagonistic and intrinsic activity of an imidazodiazepine derivative, Ro 15-1788, was manifested on the crossed extensor reflex. Ro 15-1788 antagonized the depressant effect of diazepam and shifted the dose-response curve of diazepam to the right in a parallel manner but could not reverse the depression produced by either phenobarbital or chlorpromazine. Ro 15-1788 also antagonized the enhancement produced by ethyl-beta-carboline-3-carboxylate. When administered alone, Ro 15-1788 showed a weak depressant effect. Thus, Ro 15-1788 seems to be a partial agonist on the benzodiazepine receptors with weak intrinsic activity and pharmacological properties differing from those of ethyl-beta-carboline-3-carboxylate.
mesh_terms: D000818:Animals; D001570:Benzodiazepinones / Q000494:pharmacology*; D002243:Carbolines / Q000494:pharmacology; D002746:Chlorpromazine / Q000494:pharmacology; D003975:Diazepam / Q000494:pharmacology; D005442:Flumazenil; D008297:Male; D010634:Phenobarbital / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000187:drug effects*; D012018:Reflex / Q000187:drug effects*
chemical_list: D001570:Benzodiazepinones; D002243:Carbolines; D011963:Receptors, GABA-A; D005442:Flumazenil; C024915:beta-carboline-3-carboxylic acid ethyl ester; D003975:Diazepam; D002746:Chlorpromazine; D010634:Phenobarbital