Invariance of the density of dopamine uptake sites and dopamine metabolism in the rat brain after a chronic treatment with the dopamine uptake inhibitor GBR 12783.

A chronic treatment (10 mg/kg, twice daily during 9 days) with the dopamine uptake inhibitor GBR 12783 was performed in rats at a dose increasing their locomotor activity. Forty-eight hours after the last administration, animals were sacrificed and 3H mazindol binding was performed on brain slices. Autoradiographic analysis revealed no change in this binding relatively to control animals in regions with high dopamine contents: striatum, nucleus accumbens, olfactory tubercle, substantia nigra and ventral tegmentum area. The treatment did not either modify the levels of dopamine (DA) and metabolites (HVA, DOPAC) both in the striatum and the nucleus accumbens. Thus, early after the end of the treatment, the chronic blockade of the dopamine uptake complex regulates neither the dopamine uptake complex nor the dopamine metabolism.