Dopamine receptors status after unilateral nigral 6-OHDA lesion. Autoradiographic and in situ hybridization study in the rat brain.
The physiological effects of dopamine (DA) are mediated by several distinct receptor subtypes. The effects of unilateral nigral 6-hydroxydopamine (6-OHDA) lesions on DA receptors were investigated by receptor autoradiography using the D1 selective ligand [3H]SCH 23390 as well as the D2 ligand [3H]spiroperidol. mRNA distribution was studied by in situ hybridization. Lesioned rats were sacrificed at different time intervals. Receptor binding studies were performed on tissue sections using selective ligands. [35S]UTP labeled RNA probes were prepared from the different cDNA (D1, D2, D3) and used for in situ hybridization. A specific loss of receptor binding sites and mRNA hybridization was found in the lesioned substantia nigra pars compacta (SNc) at all times examined. Receptor binding studies revealed a different time-dependent increase in both D1 and D2 receptors. In situ hybridization showed that only D2 receptor mRNA increased in the caudate-putamen (CPu) of the lesioned side 15 d after 6-OHDA. No changes were observed in D1 and D3 receptor mRNA during the entire time-course.
Fornaretto
M G
MG
Department of Neurobiology, Farmitalia Carlo Erba-Erbamont Group, Nerviano, Milan, Italy.
Caccia
C
C
Caron
M G
MG
Fariello
R G
RG
D000818:Animals; D001345:Autoradiography; D001552:Benzazepines / Q000494:pharmacology; D017403:In Situ Hybridization; D008297:Male; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D016627:Oxidopamine / Q000633:toxicity*; D015347:RNA Probes; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D011954:Receptors, Dopamine / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D017447:Receptors, Dopamine D1 / Q000235:genetics / Q000378:metabolism; D017448:Receptors, Dopamine D2 / Q000235:genetics / Q000378:metabolism; D050637:Receptors, Dopamine D3; D013134:Spiperone / Q000494:pharmacology; D013378:Substantia Nigra / Q000033:anatomy & histology / Q000187:drug effects*; D013462:Sulfur Radioisotopes
D001552:Benzazepines; C493595:Drd3 protein, rat; D009419:Nerve Tissue Proteins; D015347:RNA Probes; D012333:RNA, Messenger; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D013462:Sulfur Radioisotopes; D013134:Spiperone; D016627:Oxidopamine