ArticleEuropean journal of pharmacology2008
Comparison of the opioid receptor antagonist properties of naltrexone and 6 beta-naltrexol in morphine-naïve and morphine-dependent mice.
Article in European journal of pharmacology, 2008. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 13 papers.
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Who cites it
13 citing papers in PubMed, 24 citations in OpenAlex.
- Intermittent marijuana use is associated with improved retention in naltrexone treatment for opiate-dependence.The American journal on addictionsTrial
- Nalmefene and naltrexone reduce alcohol intake via selective efficacy in subpopulations distinguished by behavioral and blood-based biomarkers.Communications medicine · 2026Article
- Ligand-Free Signaling of G-Protein-Coupled Receptors: Relevance to μ Opioid Receptors in Analgesia and Addiction.Molecules (Basel, Switzerland) · 2022Review
- N-Demethylsinomenine, an active metabolite of sinomenine, attenuates chronic neuropathic and inflammatory pain in mice.Scientific reports · 2021Article
- Enhanced Intranasal Absorption of Naltrexone by Dodecyl Maltopyranoside: Implications for the Treatment of Opioid Overdose.Journal of clinical pharmacology · 2019Article
- Role of the guanine nucleotide binding protein, GαPsychopharmacology · 2018Article
- Isobolographic analysis of the opioid-opioid interactions in a tonic and a phasic mouse model of induced nociceptive pain.Journal of biomedical science · 2014Article
- Role of meningeal mast cells in intrathecal morphine-evoked granuloma formation.Anesthesiology · 2013Article
- Analgesic tone conferred by constitutively active mu opioid receptors in mice lacking β-arrestin 2.Molecular pain · 2011Article
- The relative potency of inverse opioid agonists and a neutral opioid antagonist in precipitated withdrawal and antagonism of analgesia and toxicity.The Journal of pharmacology and experimental therapeutics · 2009Article
- Shadows across mu-Star? Constitutively active mu-opioid receptors revisited.British journal of pharmacology · 2009Article
- Neutral antagonist activity of naltrexone and 6beta-naltrexol in naïve and opioid-dependent C6 cells expressing a mu-opioid receptor.British journal of pharmacology · 2009Article
- Relative potency of the opioid antagonists naloxone and 6-alpha-naloxol to precipitate withdrawal from acute morphine dependence varies with time post-antagonist.Pharmacology, biochemistry, and behavior · 2009Article
Corrections and comments
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Authors and funding
3 authors at 1 institution in 1 country.
Funding
Abstract
It has been proposed that on chronic morphine treatment the micro-opioid receptor becomes constitutively active, and as a consequence, the opioid withdrawal response arises from a reduction in the level of this constitutively active receptor. In support of this, the putative micro-opioid receptor inverse agonist naltrexone has been shown to precipitate more severe withdrawal behavior in mice than the putative neutral receptor antagonist 6 beta-naltrexol. In the present study naltrexone and 6 beta-naltrexol were compared in NIH Swiss mice to test the hypothesis that their differential ability to precipitate withdrawal is due to differences in their in vivo opioid receptor antagonist potencies caused by differential access to micro-opioid receptors in the central nervous system and not necessarily by intrinsic differences in their opioid receptor activity. In naïve mice both compounds had similar potencies to antagonize morphine-induced antinociception in the hot plate and warm-water tail-withdrawal assays when measured under equilibrium conditions and afforded similar calculated apparent in vivo micro-opioid receptor affinities. In morphine-dependent mice both compounds precipitated withdrawal jumping but naltrexone was between 10- and 100-fold more potent than 6 beta-naltrexol. A similar potency difference was seen for other withdrawal behaviors. Both naltrexone and 6 beta-naltrexol at 1 mg/kg reversed antinociception induced by the long-lasting micro-opioid receptor agonist BU72 in the warm-water tail-withdrawal assay, but antagonism by naltrexone was 6-fold more rapid in onset at equal doses. Since the compounds have similar affinity for the micro-opioid receptor in vivo, the results suggest that the differences observed between the ability of naltrexone and 6 beta-naltrexol to precipitate withdrawal in the mouse may be explained by differential onset of receptor antagonist action.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.