Effects of piribedil on noradrenaline and MOPEG-SO4 levels in the rat brain

I.p. administration of piribedil methansulphonate to male Sprague-Dawley rats resulted in a remarkable increase of brain MOPEG-SO4 which was consistent over time. In parallel experiments brain content of NA was found significantly reduced 30 and 60 min after drug administration. The effect seems to be dose dependent. These data cast some doubts on the relative specificity of action of piribedil as a dopaminergic activator.