Supersensitivity of quinpirole-evoked GTPase activation without changes in gene expression of D2 and Gi protein in the striatum of hemi-dopaminergic lesioned rats.
Quinpirole with D2 agonist activity showed a two-fold increase in the GTPase activity in the 6-hydroxydopamine-lesioned side of the striatum, compared with that in the control side. However, neither qualitative nor quantitative changes were observed in the gene expression of two alternative splicing products derived from dopamine D2 receptor gene or of Gil alpha, in the RNAase protection assay. These results suggest that D2 receptor-mediated supersensitization does not come from the D2 receptor upregulation.
Department of Pharmacology, Yokohama City University, Japan.
A
A
Inoue
H
H
Ueda
Y
Y
Nakata
Y
Y
Misu
D000818:Animals; D001483:Base Sequence; D002462:Cell Membrane / Q000378:metabolism; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D017931:DNA Primers; D004298:Dopamine / Q000502:physiology; D018491:Dopamine Agonists / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D004873:Ergolines / Q000494:pharmacology*; D020558:GTP Phosphohydrolases / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000096:biosynthesis*; D015870:Gene Expression; D008297:Male; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D019257:Quinpirole; D051381:Rats; D017207:Rats, Sprague-Dawley; D017448:Receptors, Dopamine D2 / Q000096:biosynthesis*; D012016:Reference Values; D013469:Sulpiride / Q000494:pharmacology
D017931:DNA Primers; D018491:Dopamine Agonists; D004873:Ergolines; D017448:Receptors, Dopamine D2; D019257:Quinpirole; D013469:Sulpiride; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; D004298:Dopamine