Autoradiographic analysis of dopamine receptor-stimulated [(35)S]GTPgammaS binding in rat striatum.
Autoradiographic analysis of [(35)S]GTPgammaS binding was used to investigate functional activation of dopamine receptors in rat striatum. Dopamine-stimulated [(35)S]GTPgammaS binding was observed with a maximal increase of 38% over basal activity. A similar stimulatory response was obtained with the D(2) agonist quinpirole, but not SKF-238393, a D(1) agonist. The effect of dopamine was blocked by the D(2) antagonist raclopride, but was unaffected by SCH-23990, a D(1) antagonist. There appeared to be a differential distribution of dopamine-stimulated [(35)S]GTPgammaS binding, with the lowest activity obtained in the medial portion of the caudal striatum. These results demonstrate, using an autoradiographic approach, (i) that dopamine stimulated [(35)S]GTPgammaS binding in the rat striatum occurs through activation of D(2) receptors, and (ii) that the effects of dopamine activation vary in different areas of the rat striatum.
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The Parkinson's Institute, 1170 Morse Avenue, Sunnyvale, CA 94089, USA.
Di Monte
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DA
Langston
J W
JW
Quik
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D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology; D000818:Animals; D001345:Autoradiography; D003342:Corpus Striatum / Q000378:metabolism*; D018491:Dopamine Agonists / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000494:pharmacology; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism / Q000494:pharmacology*; D008297:Male; D019257:Quinpirole / Q000494:pharmacology; D020891:Raclopride / Q000494:pharmacology; D011869:Radioligand Assay / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011954:Receptors, Dopamine / Q000378:metabolism*; D013462:Sulfur Radioisotopes
D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D011954:Receptors, Dopamine; D013462:Sulfur Radioisotopes; D019257:Quinpirole; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D020891:Raclopride; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine