ArticleBritish journal of pharmacology2006
Decreased mu-opioid receptor signalling and a reduction in calcium current density in sensory neurons from chronically morphine-treated mice.
Article in British journal of pharmacology, 2006. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 12 papers.
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12 citing papers in PubMed, 26 citations in OpenAlex.
- Evaluation of microRNA let-7b-3p expression levels in methamphetamine abuse.Revista da Associacao Medica Brasileira (1992) · 2023Article
- Opioid-Induced Hyperalgesia Is Associated with Dysregulation of Circadian Rhythm and Adaptive Immune Pathways in the Mouse Trigeminal Ganglia and Nucleus Accumbens.Molecular neurobiology · 2019Article
- β-Arrestin-2 knockout prevents development of cellular μ-opioid receptor tolerance but does not affect opioid-withdrawal-related adaptations in single PAG neurons.British journal of pharmacology · 2015Article
- Analgesic tolerance to morphine is regulated by PPARγ.British journal of pharmacology · 2014Article
- Spider peptide Phα1β induces analgesic effect in a model of cancer pain.Cancer science · 2013Article
- Mechanisms of rapid opioid receptor desensitization, resensitization and tolerance in brain neurons.British journal of pharmacology · 2012Review
- Let-7 microRNAs and Opioid Tolerance.Frontiers in genetics · 2012Article
- Morphine- and CaMKII-dependent enhancement of GIRK channel signaling in hippocampal neurons.The Journal of neuroscience : the official journal of the Society for Neuroscience · 2010Article
- Regulation of opioid tolerance by let-7 family microRNA targeting the mu opioid receptor.The Journal of neuroscience : the official journal of the Society for Neuroscience · 2010Article
- How to design an opioid drug that causes reduced tolerance and dependence.Annals of neurology · 2010Article
- Endogenous opiates and behavior: 2006.Peptides · 2007Review
- Effects of receptor density on Nociceptin/OrphaninFQ peptide receptor desensitisation: studies using the ecdysone inducible expression system.Naunyn-Schmiedeberg's archives of pharmacology · 2007Article
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Authors and funding
4 authors at 2 institutions in 1 country.
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No grant is acknowledged in the PubMed record.
Abstract
Sensory neurons are a major site of opioid analgesic action, but the effect of chronic morphine treatment (CMT) on mu-opioid receptor function in these cells is unknown. We examined mu-opioid receptor modulation of calcium channel currents (I(Ca)) in small trigeminal ganglion (TG) neurons from mice chronically treated with morphine and measured changes in mu-opioid receptor mRNA levels in whole TG. Mice were injected subcutaneously with 300 mg kg(-1) of morphine base in a slow release emulsion three times over 5 days, or with emulsion alone (vehicles). CMT mice had a significantly reduced response to the acute antinociceptive effects of 30 mg kg(-1) morphine compared with controls (P=0.035).Morphine inhibited I(Ca) in neurons from CMT (EC(50) 300 nM) and vehicle (EC(50) 320 nM) mice with similar potency, but morphine's maximum effect was reduced from 36% inhibition in vehicle to 17% in CMT (P<0.05). Similar results were observed for the selective mu-opioid agonist Tyr-D-Ala-Gly-N-Me-Phe-Gly-ol enkephalin (DAMGO). Inhibition of I(Ca) by the GABA(B) agonist baclofen was unaffected by CMT. In neurons from CMT mice, there were significant reductions in P/Q-type (P=0.007) and L-type (P=0.002) I(Ca) density.mu-Opioid receptor mRNA levels were not altered by CMT. These data demonstrate that CMT produces a significant reduction of the effectiveness of mu-opioid agonists to inhibit I(Ca) in TG sensory neurons, accompanied by a reduction in I(Ca) density. Thus, adaptations in sensory neurons may mediate some of the tolerance to the antinociceptive effects of morphine that develop during systemic administration.
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