Chronic treatment of rats with SCH-23390 or raclopride does not affect the concentrations of DARPP-32 or its mRNA in dopamine-innervated brain regions.
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.
Grebb
J A
JA
Laboratory of Molecular and Cellular Neuroscience, Rockefeller University, New York, NY 10021-6399.
Girault
J A
JA
Ehrlich
M
M
Greengard
P
P
D000818:Animals; D001552:Benzazepines / Q000494:pharmacology*; D001923:Brain Chemistry / Q000187:drug effects*; D004298:Dopamine / Q000502:physiology*; D018492:Dopamine Antagonists; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D008297:Male; D009419:Nerve Tissue Proteins / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D009994:Osmolar Concentration; D010750:Phosphoproteins / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D020891:Raclopride; D051381:Rats; D011919:Rats, Inbred Strains; D012457:Salicylamides / Q000494:pharmacology*
D001552:Benzazepines; D018492:Dopamine Antagonists; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D009419:Nerve Tissue Proteins; D010750:Phosphoproteins; D012333:RNA, Messenger; D012457:Salicylamides; D020891:Raclopride; D004298:Dopamine