Activation of α4β2*/α6β2* nicotinic receptors alleviates anxiety during nicotine withdrawal without upregulating nicotinic receptors

J Pharmacol Exp Ther. 2014 May;349(2):348-54. doi: 10.1124/jpet.113.211706. Epub 2014 Mar 13.

Abstract

Although nicotine mediates its effects through several nicotinic acetylcholine receptor (nAChR) subtypes, it remains to be determined which nAChR subtypes directly mediate heightened anxiety during withdrawal. Relative success in abstinence has been found with the nAChR partial agonist varenicline (Chantix; Pfizer, Groton, CT); however, treatment with this drug fails to alleviate anxiety in individuals during nicotine withdrawal. Therefore, it is hypothesized that success can be found by the repurposing of other nAChR partial agonists for cessation therapies that target anxiety. It is noteworthy that the selective partial agonists for α4β2, ABT-089 [2-methyl-3-[2(S)-pyrrolidinylmethoxy]pyridine], and α7, ABT-107 [5-(6-[(3R)-1-azabicyclo[2.2.2]oct-3-yloxy] pyridazin-3-yl)-1H-indole] (AbbVie, North Chicago, IL), have not been evaluated as possible therapeutics for nicotine cessation. Therefore, we examined the effect of ABT-089 and ABT-107 on anxiety during withdrawal from nicotine in the novelty-induced hypophagia (NIH) paradigm. We found that short-term administration of ABT-089 and ABT-107 alleviate anxiety-like behavior during withdrawal from nicotine while long-term administration of ABT-089 but not ABT-107 reduces anxiety-like behavior during withdrawal. After behavioral testing, brains were harvested and β2-containing nAChRs were measured using [(3)H]epibaditine. ABT-089 and ABT-107 do not upregulate nAChRs, which is in contrast to the upregulation of nAChRs observed after nicotine. Furthermore, ABT-089 is anxiogenic in nicotine naive animals, suggesting that the effects on anxiety are specifically related to the nicotine-dependent state. Together, these studies identify additional nAChR partial agonists that may aid in the rational development of smoking cessation aids.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Anti-Anxiety Agents / pharmacology*
  • Anti-Anxiety Agents / therapeutic use
  • Anxiety / drug therapy*
  • Anxiety / metabolism
  • Anxiety / psychology
  • Brain / metabolism
  • Drug Partial Agonism
  • Indoles / pharmacology*
  • Indoles / therapeutic use
  • Male
  • Mice
  • Nicotine / adverse effects*
  • Nicotinic Agonists / pharmacology*
  • Nicotinic Agonists / therapeutic use
  • Pyridines / pharmacology*
  • Pyridines / therapeutic use
  • Pyrrolidines / pharmacology*
  • Pyrrolidines / therapeutic use
  • Quinuclidines / pharmacology*
  • Quinuclidines / therapeutic use
  • Radioligand Assay
  • Receptors, Nicotinic / metabolism*
  • Substance Withdrawal Syndrome / drug therapy*
  • Substance Withdrawal Syndrome / metabolism
  • Substance Withdrawal Syndrome / psychology
  • Time Factors
  • Up-Regulation

Substances

  • 5-(6-(1-azabicyclo(2,2,2)oct-3-yloxy)pyridazin-3-yl)-1H-indole
  • Anti-Anxiety Agents
  • Indoles
  • Nicotinic Agonists
  • Pyridines
  • Pyrrolidines
  • Quinuclidines
  • Receptors, Nicotinic
  • alpha6beta2 nicotinic acetylcholine receptor
  • nicotinic receptor alpha4beta2
  • Nicotine
  • pozanicline