Effects of alpha4beta2 and alpha7 nicotinic acetylcholine receptor antagonists on place aversion induced by naloxone in single-dose morphine-treated rats.
Acute dependence can be observed when naloxone is administered 24 h after even a single dose of morphine, and nicotine attenuates this naloxone-precipitated withdrawal syndrome. This acute dependence has been hypothesized to be associated with a dopaminergic mechanism. In the present study, the role of nicotinic acetylcholine receptor subtypes in the place aversion induced by naloxone in single-dose morphine-treated rats was investigated. Methyllycaconitine (1, 2 and 5 mg/kg), an alpha7 nicotinic acetylcholine receptor subtype inhibitor, significantly and dose dependently inhibited the attenuating effect of nicotine on naloxone-induced place aversion. In contrast, dihydroxy-beta-erithroidine (1, 2 and 5 mg/kg), an alpha4beta2 nicotinic acetylcholine receptor subtype inhibitor, did not have any effect on the attenuating effect of nicotine on naloxone-induced place aversion. These findings suggested that the alpha7 nicotinic acetylcholine receptor subtype is associated with the place aversion induced by naloxone in single-dose morphine-treated rats. Nicotinic acetylcholine receptor subtype inhibitors warrant further study as possible treatment for acute dependence.
Motoshima
Seiki
S
Onomichi Municipal Hospital Hiroshima, 3-1170-177 Shintakayama, Onomichi, Hiroshima 722-8503, Japan.
Suemaru
Katsuya
K
Kawasaki
Youichi
Y
Jin
Chunyu
C
Kawasaki
Hiromu
H
Gomita
Yutaka
Y
Araki
Hiroaki
H
D000157:Aconitine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects* / Q000502:physiology; D004079:Dihydro-beta-Erythroidine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology*; D009292:Narcotic Antagonists / Q000494:pharmacology; D009294:Narcotics / Q000494:pharmacology; D009538:Nicotine / Q000494:pharmacology; D018722:Nicotinic Agonists / Q000494:pharmacology; D018733:Nicotinic Antagonists / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011978:Receptors, Nicotinic / Q000502:physiology; D064569:alpha7 Nicotinic Acetylcholine Receptor
C579165:Chrna7 protein, rat; D009292:Narcotic Antagonists; D009294:Narcotics; D018722:Nicotinic Agonists; D018733:Nicotinic Antagonists; D011978:Receptors, Nicotinic; D064569:alpha7 Nicotinic Acetylcholine Receptor; C403531:nicotinic receptor alpha4beta2; C054634:methyllycaconitine; D004079:Dihydro-beta-Erythroidine; D009270:Naloxone; D009538:Nicotine; D009020:Morphine; D000157:Aconitine