Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
AUTORADIOGRAPHIC AND SPECT IMAGING OF CEREBRAL OPIOID RECEPTORS WITH AN I-123 LABELED ANALOG OF DIPRENORPHINE
Autore:
LEVER JR; ILGIN N; MUSACHIO JL; SCHEFFEL U; FINLEY PA; FLESHER JE; NATARAJAN TK; WAGNER HN; FROST JJ;
Indirizzi:
JOHNS HOPKINS UNIV,SCH HYG & PUBL HLTH,DEPT ENVIRONM HLTH SCI,ROOM 2001,615 N WOLFE ST BALTIMORE MD 21205 JOHNS HOPKINS UNIV,SCH HYG & PUBL HLTH,DEPT RADIOL BALTIMORE MD 21205
Titolo Testata:
Synapse
fascicolo: 2, volume: 29, anno: 1998,
pagine: 172 - 182
SICI:
0887-4476(1998)29:2<172:AASIOC>2.0.ZU;2-I
Fonte:
ISI
Lingua:
ENG
Soggetto:
POSITRON EMISSION TOMOGRAPHY; TEMPORAL-LOBE EPILEPSY; MU-OPIATE RECEPTORS; LIVING HUMAN-BRAIN; C-11 DIPRENORPHINE; N1'-()C-11>METHYL) NALTRINDOLE; NORMAL VOLUNTEERS; INVIVO BINDING; HIGH-AFFINITY; QUANTIFICATION;
Keywords:
SPECT; OPIOID RECEPTORS; DIPRENORPHINE; AUTORADIOGRAPHY; MOUSE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
48
Recensione:
Indirizzi per estratti:
Citazione:
J.R. Lever et al., "AUTORADIOGRAPHIC AND SPECT IMAGING OF CEREBRAL OPIOID RECEPTORS WITH AN I-123 LABELED ANALOG OF DIPRENORPHINE", Synapse, 29(2), 1998, pp. 172-182

Abstract

The feasibility of imaging cerebral opioid receptors by single photonemission computed tomography (SPECT) has been established in baboon using a novel analog of diprenorphine (DPN) radiolabeled with iodine-123. The radioligand, [I-123]-O-IA-DPN (C6-O-[I-123]iodoallyl-DPN), was prepared in good yield (80%) with high radiochemical purity (>97%) andhigh specific radioactivity (>2,400 mCi/mu mol). In ex vivo autoradiographic studies, with and without naltrexone blockade, [I-I23]-O-IA-DPN specifically labeled opioid receptors throughout the mouse brain. Nonmetabolized radioligand accounted for >90% of the signal observed in extracts of whole mouse brain. SPECT imaging trials showed that [I-123]-O-IA-DPN selectively localized in regions of baboon brain known to have high densities of opioid receptors, such as striatum, thalamus, and temporal cortex. A much lower level of radioligand uptake and retention was noted for cerebellum, a region with few opioid binding sites. Pretreatment with naltrexone (6.5 mu mol/kg) blocked [I-I23]-O-IA-DPN binding in all brain regions. Using naltrexone blockade to define the nonspecific component for a given region of interest, total to nonspecific binding ratios increased linearly (r greater than or equal to 0.98) over the SPECT study with maximal values for striatum (9.8), thalamus (7.1), and temporal cortex (6.9) reached at the last time point investigated (3.5 h). Specific binding for these regions, assessed as thedifference between regional SPECT activity for the control and blocked states, proved irreversible over the observation period. By the end of the time course, specific [I-123]-O-IA-DPN binding was >85% of total radioactivity in regions rich in opioid receptors and 62% of total radioactivity in cerebellum. The aggregate data are consistent with visualization of multiple opioid receptor types. Thus, [I-123]-O-IA-DPN should prove useful for SPECT studies within the constraints imposed bya lack of innate selectivity for a single type of brain opioid receptor. (C) 1998 Wiley-Liss, Inc.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 29/03/20 alle ore 09:10:45