Opioid binding to rat and guinea-pig neural membranes in the presence of physiological cations at 37 degrees C

Journal Article · Sat Jun 01 04:00:00 EDT 1985 · J. Pharmacol. Exp. Ther.; (United States)

OSTI ID:5220960

Werling, L L; Zarr, G D; Brown, S R; Cox, B M

The authors have identified mu, delta and kappa opioid binding sites in four types of neural membranes under conditions which include physiological concentrations of ions and an incubation temperature of 37 degrees C. They hypothesize that binding parameters determined under these conditions should be more directly comparable with physiological experiments than parameters obtained under conditions of low ionic concentration and at low temperature. By using either a radioligand which is selective for a single type of opioid binding site or a relatively nonselective radioligand in the presence of an unlabeled selective ligand, they have isolated binding to single populations of sites. Saturation and displacement data were analyzed with the aid of a computerized nonlinear curve fitting program. (/sup 3/H)Tyr-D-Ala-Gly-(Me)Phe-Gly-ol bound to a single population of sites with the characteristics of mu receptors, as determined by saturation and displacement analysis. Binding to the mu site represented 70% of the total specific opioid binding in rat brain, but only 20 to 30% in guinea-pig tissues. (/sup 3/H)(D-Ala2-D-Leu5)enkephalin bound almost equally well to mu and delta sites, but the delta site could be examined by the inclusion of unlabeled Tyr-D-Ala-Gly-(Me)Phe-Gly-ol in the incubations. (/sup 3/H)Ethylketocyclazocine bound mu and kappa sites, and Tyr-D-Ala-Gly-(Me)Phe-Gly-ol was also used to block the mu component in experiments in which they studied kappa binding. Binding to kappa sites represented 50 to 60% of the total in guinea-pig tissues, but less than 20% in rat brain.

• Research Organization: Uniformed Services Univ. of the Health Sciences, Bethesda, MD
• OSTI ID: 5220960
• Journal Information: J. Pharmacol. Exp. Ther.; (United States), Journal Name: J. Pharmacol. Exp. Ther.; (United States) Vol. 3; ISSN JPETA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BODY
BRAIN
CATIONS
CELL CONSTITUENTS
CELL MEMBRANES
CENTRAL NERVOUS SYSTEM
CENTRAL NERVOUS SYSTEM DEPRESSANTS
CHARGED PARTICLES
CHEMICAL BONDS
DRUGS
ENDORPHINS
ENKEPHALINS
GUINEA PIGS
IN VITRO
IONS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIGANDS
MAMMALS
MEMBRANES
NARCOTICS
NERVOUS SYSTEM
NEUROREGULATORS
ORGANIC COMPOUNDS
ORGANS
PEPTIDES
POLYPEPTIDES
PROTEINS
RATS
RECEPTORS
RODENTS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES