Abstract
Adequate treatment of tobacco addiction remains problematic. Part of the problem with treatment is a poor understanding of the pharmacologic aspects of nicotine contributing to addiction. In addition to activating nicotinic acetylcholine receptors, nicotine also desensitizes them. It is currently not known how much of each of nicotine's actions contribute to its particular behavioral effects. Sazetidine-A (saz-A) is a novel nicotinic receptor-desensitizing agent and partial agonist with high selectivity for alpha4beta2 receptors. The current experiments were conducted to determine whether saz-A would reduce nicotine self-administration in rats and to characterize its ancillary effects. Adult male Sprague-Dawley rats were allowed to self-administer nicotine. After initial food pellet training followed by 10 sessions of nicotine self-administration training, the rats were administered saz-A (0.1-3 mg/kg s.c.) or the saline vehicle in a repeated-measures counterbalanced design. Saz-A at the 3 mg/kg dose significantly decreased nicotine self-administration relative to performance of the same rats after saline injections. In a second study, long-term administration of this dose of sazetidine-A over the course of 10 sessions significantly reduced nicotine self-administration with no apparent diminution of effect. Saz-A in this dose range had only modest effects on locomotor activity, without any overall decrease in activity over a 1-h-long session. Saz-A significantly reduced food self-administration, but this effect was smaller than its effect on nicotine self-administration. Saz-A, which is a selective alpha4beta2-desensitizing agent and partial agonist, effectively reduces nicotine self-administration. This type of treatment holds promise for a new therapy to aid smoking cessation.