Dopamine transporter binding in rat striatum and nucleus accumbens is unaltered following chronic changes in dopamine levels.
The effects of chronic treatment with the tyrosine hydroxylase inhibitor alpha-methyltyrosine or the dopamine precursor 1-3,4-dihydroxyphenylalanine on radioligand binding to the dopamine transporter in homogenates of rat striatum and nucleus accumbens were assessed. Chronic alpha-methyltyrosine administration decreased dopamine levels in both the striatum and nucleus accumbens without a resulting change in [3H]mazindol binding to the dopamine transporter in either brain region. In a second experiment, chronic administration of alpha-methyltyrosine or L-3,4-dihydroxyphenylalanine produced significant decreases and increases, respectively, in striatal dopamine levels without altering the binding of [3H]WIN 35,428, a chemically distinct dopamine transporter radioligand. These data suggest that even dramatic fluctuations in brain dopamine levels do not modulate the abundance of the dopamine transporter.
Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI 48201, USA.
C A
CA
Moody
J G
JG
Granneman
M J
MJ
Bannon
D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism / Q000502:physiology*; D015259:Dopamine Agents / Q000494:pharmacology; D050483:Dopamine Plasma Membrane Transport Proteins; D007980:Levodopa / Q000494:pharmacology; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D008781:Methyltyrosines / Q000494:pharmacology; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000378:metabolism; D011485:Protein Binding; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D019805:alpha-Methyltyrosine
D002352:Carrier Proteins; D015259:Dopamine Agents; D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D008781:Methyltyrosines; D009419:Nerve Tissue Proteins; D007980:Levodopa; D019805:alpha-Methyltyrosine; D004298:Dopamine