CGS 8216, Ro 15-1788 and methyl-beta-carboline-3-carboxylate, but not EMD 41717 antagonize the muscle relaxant effect of diazepam in genetically spastic rats.
Diazepam (0.4-4 mg/kg i.p.) reduced the spontaneous tonic activity in the electromyogram (EMG) recorded from the gastrocnemius-soleus muscle of spastic mutant Han-Wistar rats in a dose-dependent manner. The muscle relaxant effect of diazepam was antagonized by the benzodiazepine antagonists Ro 15-1788 (5 mg/kg i.p.), beta-CCM (2 mg/kg i.p.) and CGS 8216 (5 mg/kg i.p.), but not by EMD 41717 (50 mg/kg i.p.). These results add further support to the hypothesis that Ro 15-1788, CGS 8216 and beta-CCM do antagonize all pharmacological effects of benzodiazepines while EMD 41717 displays more selectivity in antagonizing the different actions of benzodiazepines.
D000818:Animals; D001570:Benzodiazepinones / Q000494:pharmacology; D002243:Carbolines / Q000494:pharmacology; D003292:Convulsants / Q000494:pharmacology*; D003975:Diazepam / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004576:Electromyography; D005260:Female; D005442:Flumazenil; D007093:Imidazoles / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009126:Muscle Relaxation / Q000187:drug effects*; D009128:Muscle Spasticity / Q000503:physiopathology*; D011720:Pyrazoles / Q000494:pharmacology; D051381:Rats; D011922:Rats, Mutant Strains
D001570:Benzodiazepinones; D002243:Carbolines; D003292:Convulsants; D007093:Imidazoles; D011720:Pyrazoles; C026072:1-methyl-beta-carboline-3-carboxylic acid; D005442:Flumazenil; C033830:2-phenylpyrazolo(4,3-c)quinolin-3(5H)-one; C037595:EMD 41717; D003975:Diazepam