Differential ontogeny of multiple opioid receptors (mu, delta, and kappa)

Journal Article · Fri Mar 01 04:00:00 EST 1985 · J. Neurosci.; (United States)

OSTI ID:5480778

Spain, J W; Roth, B L; Coscia, C J

We investigated the postnatal ontogeny of opioid receptors in rat brain under assay conditions which, when combined with computerized analysis, effectively reflect the developmental profile of high affinity binding to mu, delta, and kappa subpopulations. Concentrations of mu sites were assessed with the selective ligand /sup 3/H-(D-ala2,mePhe4,gly-ol5)enkephalin (DAGO). The other two sites were analyzed in binding assays with less selective radioligands but in the presence of specific unlabeled ligands which suppress cross-reactivity. We utilized /sup 3/H-(D-ala2,D-leu5)enkephalin (DADL) in the presence of 10 nM DAGO to label delta sites and /sup 3/H-ethylketocyclazocine (EKC) in the presence of 100 nM DADL + 100 nM (D-ala2,mePhe4,Met(0)ol5)enkephalin to detect kappa receptors. After birth, the density (femtomoles per milligram of wet weight) of mu sites declined for several days and then rose sharply over the next 2 weeks, increasing 2-fold by adulthood. Delta (delta) sites appeared in the second week postnatal and increased more than 8-fold in the next 2 weeks. Levels of kappa receptors were relatively low at birth and increased slowly (2-fold, overall). Computerized analyses of binding data revealed that DAGO and DADL were binding to single populations of sites throughout the postnatal period. DAGO and EKC affinities did not fluctuate in this period, whereas DADL affinities were low for the first week and then rose to adult levels. In summary, mu, kappa, and delta receptors exhibit differential postnatal developmental profiles. The former two are present at birth, whereas the latter appears in the second week. The postnatal increase for all three sites appear to be preceded by the previously demonstrated emergence of opioid peptides.

• Research Organization: St. Louis Univ. School of Medicine, MO
• OSTI ID: 5480778
• Journal Information: J. Neurosci.; (United States), Journal Name: J. Neurosci.; (United States) Vol. 5:3; ISSN JNRSD
• Country of Publication: United States
• Language: English

Related Subjects

550801* -- Morphology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOCHEMICAL REACTION KINETICS
BODY
BRAIN
CENTRAL NERVOUS SYSTEM
DISTRIBUTION
DRUGS
ENDORPHINS
ENKEPHALINS
KINETICS
LABELLED COMPOUNDS
MAMMALS
NERVOUS SYSTEM
NEUROREGULATORS
ONTOGENESIS
ORGANIC COMPOUNDS
ORGANS
PEPTIDES
POLYPEPTIDES
PROTEINS
RATS
REACTION KINETICS
RECEPTORS
RODENTS
TISSUE DISTRIBUTION
TRITIUM COMPOUNDS
VERTEBRATES