Reversal of the muscle relaxant effect of diazepam but not of progabide by a specific benzodiazepine antagonist: Ro 15-1788.

The muscle relaxant effects of diazepam and progabide were studied in mutant Han-Wistar rats which exhibit spontaneous tonic activity in the electromyogram of the gastrocnemius-soleus muscle. Treatment with diazepam or progabide produced a dose-related reduction of the spontaneous activity measured in the electromyogram. The depressant effect of diazepam, but not that of progabide was antagonized by the specific benzodiazepine antagonist Ro 15-1788. From these data it is apparent that the muscle relaxant effect of progabide is not mediated through an alteration of benzodiazepine receptors.