Comparison between dopamine-stimulated adenylate cyclase and /sup 3/H-SCH 23390 binding in rat striatum
Methods for measuring /sup 3/H-SCH 23990 binding and dopamine (DA) stimulated adenylate cyclase (AC) were established in identical tissue preparations and under similar experimental conditions. Pharmacological characterization revealed that both assays involved interaction with the D1 receptor or closely associated sites. In order to investigate whether the binding sites for /sup 3/H-SCH 23390 and DA in fact are identical, the antagonistic effects of a variety of pharmacologically active compounds were examined. Surprisingly, the K/sub i/-values obtained from Schild-plot analysis of the antagonism of DA-stimulated AC, were 80-240 times higher than the K/sub i/-values obtained from competition curves of /sup 3/H-SCH 23390 binding. Since both assays were performed under identical conditions, the differences in K/sub i/-values indicate the possibility of different binding sites for DA and /sup 3/H-SCH 23390 or, that DA and /sup 3/-SCH 23390 label different states of the same receptor. 19 references, 7 figures, 2 tables.
- Research Organization:
- NOVO Pharmaceuticals R and D, Novo Alle, Denmark
- OSTI ID:
- 5031146
- Journal Information:
- Life Sci.; (United States), Journal Name: Life Sci.; (United States) Vol. 37:21; ISSN LIFSA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Autoradiographic localization of dopamine DA1 receptors in rat kidney with ( sup 3 H)Sch 23390
Characterization of the binding of /sup 3/H-SCH 23390, a selective D-1 receptor antagonist ligand, in rat striatum
Related Subjects
59 BASIC BIOLOGICAL SCIENCES
AMINES
ANIMALS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOASSAY
BIOCHEMICAL REACTION KINETICS
CARDIOTONICS
CARDIOVASCULAR AGENTS
COMPARATIVE EVALUATIONS
CYCLASES
DATA
DOPAMINE
DRUGS
ENZYME ACTIVITY
ENZYMES
EXPERIMENTAL DATA
HYDROXY COMPOUNDS
INFORMATION
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LYASES
MAMMALS
MUSCLES
NEUROREGULATORS
NUMERICAL DATA
ORGANIC COMPOUNDS
PHENOLS
POLYPHENOLS
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SYMPATHOMIMETICS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES