Receptor-selective changes in µ-, δ- and κ-opioid receptors after chronic naltrexone treatment in mice

Chronic treatment with the opioid antagonist naltrexone induces functional supersensitivity to opioid agonists, which may be explained by receptor up‐regulation induced by opioid receptor blockade. In the present study, the levels of opioid receptor subtypes through the brain of mice were determined...

Full description

Saved in:
Bibliographic Details
Published in:The European journal of neuroscience 2003-03, Vol.17 (5), p.1006-1012
Main Authors: Lesscher, Heidi M. B., Bailey, Alexis, Burbach, J. Peter H., Van Ree, Jan M., Kitchen, Ian, Gerrits, Mirjam A. F. M.
Format: Article
Language:English
Subjects:
Animals
Autoradiography
Brain - drug effects
Brain - metabolism
Image Processing, Computer-Assisted
Male
Mice
naltrexone
Naltrexone - pharmacology
Narcotic Antagonists - pharmacology
opioid
receptor
Receptors, Opioid - drug effects
Receptors, Opioid - metabolism
Receptors, Opioid, delta - drug effects
Receptors, Opioid, delta - metabolism
Receptors, Opioid, kappa - drug effects
Receptors, Opioid, kappa - metabolism
Receptors, Opioid, mu - drug effects
Receptors, Opioid, mu - metabolism
regulation
Signal Transduction - drug effects
Time Factors
Up-Regulation
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Chronic treatment with the opioid antagonist naltrexone induces functional supersensitivity to opioid agonists, which may be explained by receptor up‐regulation induced by opioid receptor blockade. In the present study, the levels of opioid receptor subtypes through the brain of mice were determined after chronic naltrexone treatment using quantitative in vitro autoradiography. This is the first complete mapping study in mice for µ‐, δ‐ and κ‐opioid receptors after chronic naltrexone exposure. Treatment with naltrexone clearly induced up‐regulation of µ‐ (mean 80%) and, to a lesser extent, δ‐opioid receptors (mean 39%). The up‐regulation of µ‐ and δ‐opioid receptors was evident throughout the brain, although there was variation in the percentage change across brain regions. In contrast, consistent up‐regulation of κ‐opioid receptors was observed in cortical structures only and was not so marked as for µ‐ and δ‐opioid receptors. In noncortical regions κ‐opioid receptor expression was unchanged. Taken together, the present findings suggest opioid receptor subtype‐selective regulation by chronic naltrexone treatment in mice.
ISSN:0953-816X
1460-9568
DOI:10.1046/j.1460-9568.2003.02502.x