Mu receptor binding of some commonly used opioids and their metabolites

Journal Article · Mon Dec 31 23:00:00 EST 1990 · Life Sciences; (USA)

DOI:https://doi.org/10.1016/0024-3205(91)90150-A· OSTI ID:5685307

Chen, Zhaorong; Irvine, R J ^[1]; Somogyi, A A; Bochner, F ^[2]

---

1. Univ. of Adelaide (Australia)
2. Univ. of Adelaide (Australia) Royal Adelaide Hospital (Australia)

The binding affinity to the {mu} receptor of some opioids chemically related to morphine and some of their metabolites was examined in rat brain homogenates with {sup 3}H-DAMGO. The chemical group at position 6 of the molecule had little effect on binding. Decreasing the length of the alkyl group at position 3 decreased the K{sub i} values (morphine < codeine < ethylmorphine < pholcodine). Analgesics with high clinical potency containing a methoxyl group at position 3 had relatively weak receptor binding, while their O-demethylated metabolites had much stronger binding. Many opioids may exert their pharmacological actions predominantly through metabolites.

• OSTI ID: 5685307
• Journal Information: Life Sciences; (USA), Journal Name: Life Sciences; (USA) Vol. 48:23; ISSN 0024-3205; ISSN LIFSA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOCHEMICAL REACTION KINETICS
DRUGS
ENDORPHINS
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
KINETICS
MEMBRANE PROTEINS
METABOLISM
METABOLITES
NEUROREGULATORS
ORGANIC COMPOUNDS
PROTEINS
REACTION KINETICS
RECEPTORS
TRACER TECHNIQUES
TRITIUM COMPOUNDS