Enhanced binding of morphine and nalorphine to opioid delta receptor by glucuronate and sulfate conjugations at the 6-position
Effect of the modification of morphine and nalorphine by glucuronate and sulfate conjugations at the 3- and 6-positions on the binding to opioid receptors was examined in a particulate fraction of rat brain. Competing potencies of both drugs against (/sup 3/H)morphine and (/sup 3/H)leucine enkephalin bindings were extremely decreased by either glucuronate or sulfate conjugation at the 3-position. On the other hand, the potencies of morphine and nalorphine against (/sup 3/H)leucine enkephalin binding were considerably enhanced by the conjugations at the 6-position, whereas the potencies against (/sup 3/H)morphine binding were decreased. These altered interactions of the conjugates at the 6-position with the two ligands were attributed to their enhanced binding to delta-receptor and reduced binding to /sup +/-receptor by Hill plot and modified Scatchard analysis. Resulted comparable and simultaneous interactions with ..mu..- and delta- receptors were assumed to be a cause of the enhanced ..mu..-receptor-directed analgesia of morphine and elevated same receptor-directed antagonistic effect of nalorphine, which have been found previously in the authors laboratory. 24 references, 2 figures, 1 table.
- Research Organization:
- Kyushu Univ., Fukuoka, Japan
- OSTI ID:
- 6075922
- Journal Information:
- Life Sci.; (United States), Journal Name: Life Sci.; (United States) Vol. 41:12; ISSN LIFSA
- Country of Publication:
- United States
- Language:
- English
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59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
ALKALOIDS
AMINO ACIDS
ANALGESICS
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOCHEMICAL REACTION KINETICS
BODY
BRAIN
CARBOXYLIC ACIDS
CENTRAL NERVOUS SYSTEM
CENTRAL NERVOUS SYSTEM DEPRESSANTS
DATA
DRUGS
ENDORPHINS
EXPERIMENTAL DATA
GLUCURONIC ACID
HYDROXY ACIDS
INFORMATION
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LEUCINE
LIGANDS
MAMMALS
MEMBRANE PROTEINS
MORPHINE
NARCOTICS
NERVOUS SYSTEM
NEUROREGULATORS
NUMERICAL DATA
OPIUM
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
OXYGEN COMPOUNDS
PROTEINS
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SULFATES
SULFUR COMPOUNDS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES