Effect of fluphenazine on tissue noradrenaline concentrations and its interaction with pargyline

Fluphenazine caused a small decrease in the noradrenaline (NA) concentrations of the rat brain, possibly by impairing granular amine storage. The drug diminished the rise in brain and heart NA concentrations induced by pargyline, suggesting that it might posses inhibitory properties on neuronal uptake mechanisms and/or NA synthesis. Fluphenazine abolished conditioned avoidance responses in rats, an effect which was maintained after the concomitant administration of pargyline, when NA concentrations remained high. This suggests that the fluphenazine-induced sedation is not mediated via its effect on brain NA content, but is possibly due to the effect of the drug on NA turnover rates in the brain.