Discrete mapping of brain Mu and delta opioid receptors using selective peptides: Quantitative autoradiography, species differences and comparison with kappa receptors

Journal Article · Mon May 01 00:00:00 EDT 1989 · Peptides (Fayetteville, New York); (USA)

DOI:https://doi.org/10.1016/0196-9781(89)90135-6· OSTI ID:5481999

Sharif, N A; Hughes, J ^[1]

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1. Addenbrookes Hospital Site, Cambridge (England)

The opioid peptides, (3H)DAGO and (3H)DPDPE, bound to rat and guinea pig brain homogenates with a high, nanomolar affinity and to a high density of mu and delta receptors, respectively. (3H)DAGO binding to mu receptors was competitively inhibited by unlabelled opioids with the following rank order of potency: DAGO greater than morphine greater than DADLE greater than naloxone greater than etorphine much greater than U50488 much greater than DPDPE. In contrast, (3H)DPDPE binding to delta receptors was inhibited by compounds with the following rank order of potency: DPDPE greater than DADLE greater than etorphine greater than dynorphin(1-8) greater than naloxone much greater than U50488 much greater than DAGO. These profiles were consistent with specific labelling of the mu and delta opioid receptors, respectively. In vitro autoradiographic techniques coupled with computer-assisted image analyses revealed a discrete but differential anatomical localization of mu and delta receptors in the rat and guinea pig brain. In general, mu and delta receptor density in the rat exceeded that in the guinea pig brain and differed markedly from that of kappa receptors in these species. However, while mu receptors were distributed throughout the brain with hotspots in the fore-, mid- and hindbrain of the two rodents, the delta sites were relatively diffusely distributed, and were mainly concentrated in the forebrain with particularly high levels within the olfactory bulb (OB), n. accumbens and striatum. Notable regions of high density of mu receptors in the rat and guinea pig brain were the accessory olfactory bulb, striatal patches and streaks, amygdaloid nuclei, ventral hippocampal subiculum and dentate gyrus, numerous thalamic nuclei, geniculate bodies, central grey, superior and inferior colliculi, solitary and pontine nuclei and s. nigra.

• OSTI ID: 5481999
• Journal Information: Peptides (Fayetteville, New York); (USA), Journal Name: Peptides (Fayetteville, New York); (USA) Vol. 10:3; ISSN PPTDD; ISSN 0196-9781
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
AUTORADIOGRAPHY
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL LOCALIZATION
BIOLOGICAL VARIABILITY
BODY
BRAIN
CELL CONSTITUENTS
CELL MEMBRANES
CENTRAL NERVOUS SYSTEM
COMPUTER CALCULATIONS
CPB
DRUGS
ENDORPHINS
GENETIC VARIABILITY
GUINEA PIGS
HYDROGEN COMPOUNDS
KINETICS
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
NERVOUS SYSTEM
NEUROREGULATORS
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SPINAL CORD
TRITIUM COMPOUNDS
VERTEBRATES