Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
QUANTITATIVE AUTORADIOGRAPHIC STUDIES OF DOPAMINE D-3 RECEPTORS IN RAT CEREBELLUM USING [I-125] S(-)5-OH-PIPAT
Autore:
VESSOTSKIE JM; KUNG MP; CHUMPRADIT S; KUNG HF;
Indirizzi:
UNIV PENN,DEPT PHARMACOL PHILADELPHIA PA 19104 UNIV PENN,DEPT RADIOL PHILADELPHIA PA 19104
Titolo Testata:
Brain research
fascicolo: 1, volume: 778, anno: 1997,
pagine: 89 - 98
SICI:
0006-8993(1997)778:1<89:QASODD>2.0.ZU;2-X
Fonte:
ISI
Lingua:
ENG
Soggetto:
INSITU HYBRIDIZATION HISTOCHEMISTRY; H-3 QUINPIROLE BINDING; MESSENGER-RNA; D3 RECEPTORS; CELL-LINE; BRAIN; 2-AMINOTETRALINS; LOCALIZATION; EXPRESSION; LIGAND;
Keywords:
GTP SENSITIVITY; AGONIST BINDING; RADIOIODINATED LIGAND; RAT BRAIN;
Tipo documento:
Article
Natura:
Periodico
Citazioni:
35
Recensione:
Indirizzi per estratti:
Citazione:
J.M. Vessotskie et al., "QUANTITATIVE AUTORADIOGRAPHIC STUDIES OF DOPAMINE D-3 RECEPTORS IN RAT CEREBELLUM USING [I-125] S(-)5-OH-PIPAT", Brain research, 778(1), 1997, pp. 89-98

Abstract

Recently, [I-125]S(-)5-OH-PIPAT -(N-n-propyl-N-3'-iodo-2'-propenyl)amino-tetralin) was reported to be a selective radioiodinated ligand fordopamine D-2-like receptors. This ligand displayed a high binding affinity (K-d = 0.3-0.4 nM) and an agonist binding profile to dopamine D-2 and D-3 receptors expressed in HEK293 cells and dopamine D-4 receptors expressed in CHO cells. Herein, a series of studies to characterizeD-3 receptors in native tissues is presented. Based on studies of thedistribution of receptor mRNA, D-3, but not D-2, receptors are present in the rat cerebellum. Quantitative autoradiographic experiments using [I-125]S(-)5-OH-PIPAT to label molecular layers 9 and 10 of rat cerebellum were conducted. Saturation experiments demonstrated that [I-125]S(-)5-OH-PIPAT bound with high affinity (K-d = 0.1 nM) to a low density (similar to 3 fmol/mg protein) of sites in molecular layers 9 and 10 of rat cerebellum. Increasing concentrations of Gpp(NH)p, but not ATP, decreased the specific binding of [I-125]S(-)5-OH-PIPAT in rat cerebellum slices. In comparison studies, binding of [I-125]NCQ298, a dopamine D-2/D-3 receptor antagonist, with a similar affinity (K-d = 0.2 nM) for D-3 receptors as [I-125]S(-)5-OH-PIPAT, was not sensitive to Gpp(NH)p. Analysis of inhibition by S(-)5-OH-PIPAT of [I-125]NCQ298 binding to rat cerebellum resulted in two-site binding with IC50 values of 0.07 nM and 6.0 nM. In the presence of GTP (300 mu M), the data bestfit a one-site model with an IC50 value of 1.6 nM. Agonists and antagonists inhibited the binding of [I-125]S(-)5-OH-PIPAT in the cerebellum with a rank order of potency consistent with an interaction at D-3 receptors. These results indicate that [I-125]S(-)5-OH-PIPAT binds to D-3 receptors in rat cerebellum. Furthermore, [I-125]S(-)5-OH-PIPAT binds to GTP sensitive and GTP insensitive states of D-3 receptors with distinctive high and low affinity states, respectively. (C) 1997 Elsevier Science B.V.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 27/01/20 alle ore 17:52:26