Differences of binding characteristics of non-selective opiates towards and delta receptor types

Journal Article · Mon Aug 10 00:00:00 EDT 1987 · Life Sci.; (United States)

DOI:https://doi.org/10.1016/0024-3205(87)90452-8· OSTI ID:6286413

Delay-Goyet, P; Roques, B P; Zajac, J M

(TH)ET (etorphine), which is considered either as an universal ligand or a agonist, interacts with identical affinities K/sub D/ = 0.33 - 0.38 nM to hybrid cells and rabbit cerebellum, pure delta and -enriched opioid receptor preparations, respectively. In rat brain tissue, (TH)ET binding is inhibited by DAGO (Tyr-D-Ala-Gly-(Me)-Phe-Gly-ol), a selective agonist, in a competitive manner without apparent modification of the maximal number of sites. Furthermore, even at a DAGO concentration (300 nM) which should be sufficient to block (TH)ET interaction with sites, no variation in the total capacity of the tritiated ligand is observed. In contrast, DTLET (Tyr-D-Thr-Gly-Phe-Leu-Thr), a delta-preferential agonist, blocks (TH)ET binding in rat brain at a concentration able to saturate delta-sites. At higher concentrations, where DTLET cross reacts with -sites, this ligand exhibits similar properties to those of DAGO. These data are very different from those obtained with (TH)EKC (ethylketocyclazocine), another universal ligand, the binding properties of which are easily explained by the occurrence in rat brain tissue of independent sites exhibiting pharmacological profiles of , delta and kappa sites. The authors results underline the possible misinterpretation of binding data obtained by using (TH) etorphine as a non-selective ligand. 28 references, 1 figure, 2 tables.

• Research Organization: INSERM, Paris, France
• OSTI ID: 6286413
• Journal Information: Life Sci.; (United States), Vol. 41:6
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ENDORPHINS
BIOCHEMICAL REACTION KINETICS
RECEPTORS
BRAIN
EXPERIMENTAL DATA
LIGANDS
RABBITS
RATS
RESPONSE MODIFYING FACTORS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BODY
CENTRAL NERVOUS SYSTEM
DATA
DRUGS
INFORMATION
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
MAMMALS
NERVOUS SYSTEM
NEUROREGULATORS
NUMERICAL DATA
ORGANS
REACTION KINETICS
RODENTS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques