Dataset Information

CC4, a dimer of cytisine, is a selective partial agonist at ?4?2/?6?2 nAChR with improved selectivity for tobacco smoking cessation.

ABSTRACT:

Background and purpose

Many of the addictive and rewarding effects of nicotine are due to its actions on the neuronal nicotinic ACh receptor (nAChR) subtypes expressed in dopaminergic mesocorticolimbic cells. The partial agonists, cytisine and varenicline, are helpful smoking cessation aids. These drugs have a number of side effects that limit their usefulness. The aim of this study was to investigate the preclinical pharmacology of the cytisine dimer1,2-bisN-cytisinylethane (CC4).

Experimental approach

The effects of CC4 on nAChRs were investigated using in vitro assays and animal behaviours.

Key results

When electrophysiologically tested using heterologously expressed human subtypes, CC4 was less efficacious than cytisine on neuronal ?4?2, ?3?4, ?7 and muscle-type receptors, and had no effect on 5-hydroxytryptamine3 receptors. Acting through ?4?2 and ?6?2 nAChRs, CC4 is a partial agonist of nAChR-mediated striatal dopamine release and, when co-incubated with nicotine, prevented nicotine's maximal effect on this response. In addition, it had low affinity for, and was less efficacious than nicotine and cytisine on the ?3?4 and ?7-nAChR subtypes. Like cytisine and nicotine, CC4-induced conditioned place preference (CPP), and its self-administration shows an inverted-U dose-response curve. Pretreatment with non-reinforcing doses of CC4 significantly reduced nicotine-induced self-administration and CPP without affecting motor functions.

Conclusion and implications

Our in vitro and in vivo findings reveal that CC4 selectively reduces behaviours associated with nicotine addiction consistent with the partial agonist selectivity of CC4 for ?2-nAChRs. The results support the possible development of CC4 or its derivatives as a promising drug for tobacco smoking cessation.

SUBMITTER: Sala M

PROVIDER: S-EPMC3631374 | biostudies-literature | 2013 Feb

REPOSITORIES: biostudies-literature

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CC4, a dimer of cytisine, is a selective partial agonist at α4β2/α6β2 nAChR with improved selectivity for tobacco smoking cessation.

Sala Mariaelvina M Braida Daniela D Pucci Luca L Manfredi Irene I Marks Michael J MJ Wageman Charles R CR Grady Sharon R SR Loi Barbara B Fucile Sergio S Fasoli Francesca F Zoli Michele M Tasso Bruno B Sparatore Fabio F Clementi Francesco F Gotti Cecilia C

British journal of pharmacology 20130201 4

<h4>Background and purpose</h4>Many of the addictive and rewarding effects of nicotine are due to its actions on the neuronal nicotinic ACh receptor (nAChR) subtypes expressed in dopaminergic mesocorticolimbic cells. The partial agonists, cytisine and varenicline, are helpful smoking cessation aids. These drugs have a number of side effects that limit their usefulness. The aim of this study was to investigate the preclinical pharmacology of the cytisine dimer1,2-bisN-cytisinylethane (CC4).<h4>Ex ...[more]

PMID: 22957729

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