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.
Moody
C A
CA
Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI 48201, USA.
Granneman
J G
JG
Bannon
M J
MJ
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