CHRONIC TREATMENT OF RATS WITH SCH-23390 OR RACLOPRIDE DOES NOT AFFECT THE CONCENTRATIONS OF DARPP-32 OR ITS MESSENGER-RNA IN DOPAMINE-INNERVATED BRAIN-REGIONS

Abstract: DARPP‐32 (dopamine‐ and cyclic AMP‐regulated phosphoprotein, Mr= 32,000, as determined by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis) is a neuronal phosphoprotein that is enriched in neurons which possess dopamine D1 receptors, particularly striatonigral neurons. In rat brain slices, the phosphorylation state of DARPP‐32 is regulated by dopamine, acting through the dopamine D1 receptor and the adenylyl cyclase system. This study reports that chronic blockade (21 days) of either dopamine D1 receptors by SCH‐23390 or dopamine D2 receptors by raclopride does not affect the concentrations of DARPP‐32 in specific rat brain regions (striatum, thalamus, hippocampus, frontal cerebral cortical pole). Northern blot analysis indicates that the steady‐state level of DARPP‐32 mRNA in striatum is also unchanged by these treatments. Copyright © 1990, Wiley Blackwell. All rights reserved