Abstract
Morphine produces analgesia by activating mu opioid receptors encoded by the MOR-1 gene. Although morphine-6β-glucuronide (M6G), heroin and 6- acetylmorphine also are considered mu opioids, recent evidence suggests that they act through a distinct receptor mechanism. We examined this question in knockout mice containing disruptions of either the first or second coding exon of MOR-1. Mice homozygous for either MOR-1 mutation were insensitive to morphine. Heroin, 6-acetylmorphine and M6G still elicited analgesia in the exon-1 MOR-1 mutant, which also showed specific M6G binding, whereas M6G and 6-acetylmorphine were inactive in the exon-2 MOR-1 mutant. These results provide genetic evidence for a unique receptor site for M6G and heroin analgesia.
Original language | English (US) |
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Pages (from-to) | 151-156 |
Number of pages | 6 |
Journal | Nature Neuroscience |
Volume | 2 |
Issue number | 2 |
DOIs | |
State | Published - Feb 1999 |
All Science Journal Classification (ASJC) codes
- General Neuroscience