Lack of abuse potential in a highly selective dopamine D3 agonist, PF-592,379, in drug self-administration and drug discrimination in rats

Behav Pharmacol. 2012 Jun;23(3):280-91. doi: 10.1097/FBP.0b013e3283536d21.

Abstract

Dopamine D3-preferring agonists are commonly used to treat Parkinson's disease and restless leg syndrome; however, laboratory animal studies suggest that they may possess a moderate abuse potential. These studies aimed to compare the highly selective, full D3 agonist PF-592,379 to the less selective D3 agonist 7-OH-DPAT, and the indirect dopamine agonist cocaine in drug self-administration and discrimination assays. Although rats readily acquired high rates of fixed ratio (FR)1 responding for cocaine, experimentally naive rats failed to acquire responding when 7-OH-DPAT or PF-592,379 was made available during an 18-session acquisition period. Cocaine also maintained dose-dependent levels of responding when available under a FR5 or a progressive ratio (PR) schedule of reinforcement. Although 7-OH-DPAT maintained modest levels of responding when substituted under a FR5, it failed to maintain significant levels of PR responding. PF-592,379 maintained saline-like rates of responding when substituted under FR5 or PR schedules of reinforcement. Similar behavioral profiles were observed in cocaine discrimination assays, with 7-OH-DPAT partially substituting for cocaine, and PF-592,379 producing saline-like effects over a wide range of doses. Together, the results of these studies predict that highly selective D3 agonists, such as PF-592,379, will have low abuse potential in humans.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aminopyridines / pharmacology*
  • Animals
  • Cocaine / pharmacology
  • Discrimination Learning / drug effects*
  • Dopamine Agonists / pharmacology*
  • Male
  • Morpholines / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Dopamine D3 / agonists*
  • Self Administration
  • Substance-Related Disorders / etiology*
  • Tetrahydronaphthalenes / pharmacology

Substances

  • Aminopyridines
  • Dopamine Agonists
  • Morpholines
  • PF 592379
  • Receptors, Dopamine D3
  • Tetrahydronaphthalenes
  • Cocaine
  • 7-hydroxy-2-N,N-dipropylaminotetralin