[Purinergic effect of ethymisole]

A study was made of the mechanism of action of ethimizole, a drug synthesized as central stimulant in terms of structural similarity to caffeine but possessing some antagonistic pharmacological effects as regards caffeine action. Experiments on rats given intraperitoneal injections of ethimizole demonstrated a considerable increase in adenylate cyclase activity of the brain and in the ATP level. Caffeine was found to prevent the stimulant action of ethimizole on energy metabolism and adenylate cyclase activity, while adenosine to potentiate this action. The possibility of ethimizole action on brain adenosine receptors is analyzed.