Specific benzodiazepine antagonist RO15-1788 and thirst-induced drinking in the rat

Midazolam, a new water-soluble benzodiazepine, increased the water intake of water deprived rats. The effect was abolished by concurrent treatment with the benzodiazepine antagonist, RO15-1788. The lack of effect of RO15-1788 on phenobarbitone-induced hyperdipsia confirmed the specificity of the antagonist action. Alone RO15-1788 (0.3-30 mg . kg-1) had no effect on thirst-induced drinking. Thus, it was not necessary to posit the action of an endogenous benzodiazepine ligand in thirst-induced drinking.