Abstract
Recent studies implied a possible involvement of the opioid system in the central nervous system (CNS) effects of cocaine. The present study was undertaken to determine specific alterations in opioid receptor binding following repeated exposure of guinea pigs to cocaine. Animals were treated with either saline or cocaine (40 mg/kg per day; i.p.) for 7 days, sacrificed 24 h after the treatment, and various brain regions were assayed for [3H]DAMGO, [3H]DPDPE and [3H]U-69,593 binding to the three major types of opioid receptors: mu, delta and kappa, respectively. A significant down-regulation of mu-opioid receptors (65-70% of control Bmax) was detected in the frontal cortex, amygdala, thalamus and hippocampus of cocaine-treated animals. Other brain regions examined did not endure changes in mu-opioid receptor binding. In contrast, no significant change in delta-opioid receptor binding was detected at any of the brain regions investigated. Alteration in kappa-opioid receptor binding following exposure to cocaine was found only in the cerebellum: an up-regulation (136% of control Bmax) was observed. These findings indicate that repeated administration of cocaine induces differential regulation of opioid receptors. The down-regulation of mu-opioid receptors in discrete limbic regions may be associated with the addicting properties of cocaine.
| Original language | English |
|---|---|
| Pages (from-to) | 53-59 |
| Number of pages | 7 |
| Journal | Drug and Alcohol Dependence |
| Volume | 33 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 1 1993 |
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Keywords
- cocaine
- limbic brain regions
- opioid receptors
- receptor regulation
ASJC Scopus subject areas
- Medicine(all)
- Behavioral Neuroscience
- Toxicology
- Health(social science)
Cite this
Differential regulation of brain opioid receptors following repeated cocaine administration to guinea pigs. / Itzhak, Yossef.
In: Drug and Alcohol Dependence, Vol. 33, No. 1, 01.01.1993, p. 53-59.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Differential regulation of brain opioid receptors following repeated cocaine administration to guinea pigs
AU - Itzhak, Yossef
PY - 1993/1/1
Y1 - 1993/1/1
N2 - Recent studies implied a possible involvement of the opioid system in the central nervous system (CNS) effects of cocaine. The present study was undertaken to determine specific alterations in opioid receptor binding following repeated exposure of guinea pigs to cocaine. Animals were treated with either saline or cocaine (40 mg/kg per day; i.p.) for 7 days, sacrificed 24 h after the treatment, and various brain regions were assayed for [3H]DAMGO, [3H]DPDPE and [3H]U-69,593 binding to the three major types of opioid receptors: mu, delta and kappa, respectively. A significant down-regulation of mu-opioid receptors (65-70% of control Bmax) was detected in the frontal cortex, amygdala, thalamus and hippocampus of cocaine-treated animals. Other brain regions examined did not endure changes in mu-opioid receptor binding. In contrast, no significant change in delta-opioid receptor binding was detected at any of the brain regions investigated. Alteration in kappa-opioid receptor binding following exposure to cocaine was found only in the cerebellum: an up-regulation (136% of control Bmax) was observed. These findings indicate that repeated administration of cocaine induces differential regulation of opioid receptors. The down-regulation of mu-opioid receptors in discrete limbic regions may be associated with the addicting properties of cocaine.
AB - Recent studies implied a possible involvement of the opioid system in the central nervous system (CNS) effects of cocaine. The present study was undertaken to determine specific alterations in opioid receptor binding following repeated exposure of guinea pigs to cocaine. Animals were treated with either saline or cocaine (40 mg/kg per day; i.p.) for 7 days, sacrificed 24 h after the treatment, and various brain regions were assayed for [3H]DAMGO, [3H]DPDPE and [3H]U-69,593 binding to the three major types of opioid receptors: mu, delta and kappa, respectively. A significant down-regulation of mu-opioid receptors (65-70% of control Bmax) was detected in the frontal cortex, amygdala, thalamus and hippocampus of cocaine-treated animals. Other brain regions examined did not endure changes in mu-opioid receptor binding. In contrast, no significant change in delta-opioid receptor binding was detected at any of the brain regions investigated. Alteration in kappa-opioid receptor binding following exposure to cocaine was found only in the cerebellum: an up-regulation (136% of control Bmax) was observed. These findings indicate that repeated administration of cocaine induces differential regulation of opioid receptors. The down-regulation of mu-opioid receptors in discrete limbic regions may be associated with the addicting properties of cocaine.
KW - cocaine
KW - limbic brain regions
KW - opioid receptors
KW - receptor regulation
UR - http://www.scopus.com/inward/record.url?scp=0027170929&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0027170929&partnerID=8YFLogxK
U2 - 10.1016/0376-8716(93)90033-M
DO - 10.1016/0376-8716(93)90033-M
M3 - Article
VL - 33
SP - 53
EP - 59
JO - Drug and Alcohol Dependence
JF - Drug and Alcohol Dependence
SN - 0376-8716
IS - 1
ER -