The novel pyrrolidine nor-lobelane analog UKCP-110 [cis-2,5-di-(2-phenethyl)-pyrrolidine hydrochloride] inhibits VMAT2 function, methamphetamine-evoked dopamine release, and methamphetamine self-administration in rats

J Pharmacol Exp Ther. 2010 Dec;335(3):841-51. doi: 10.1124/jpet.110.172742. Epub 2010 Aug 30.

Abstract

Both lobeline and lobelane attenuate methamphetamine self-administration in rats by decreasing methamphetamine-induced dopamine release via interaction with vesicular monoamine transporter-2 (VMAT2). A novel derivative of nor-lobelane, cis-2,5-di-(2-phenethyl)-pyrrolidine hydrochloride (UKCP-110), and its trans-isomers, (2R,5R)-trans-di-(2-phenethyl)-pyrrolidine hydrochloride (UKCP-111) and (2S,5S)-trans-di-(2-phenethyl)-pyrrolidine hydrochloride (UKCP-112), were evaluated for inhibition of [(3)H]dihydrotetrabenazine binding and [(3)H]dopamine uptake by using a rat synaptic vesicle preparation to assess VMAT2 interaction. Compounds were evaluated for inhibition of [(3)H]nicotine and [(3)H]methyllycaconitine binding to assess interaction with the major nicotinic receptor subtypes. In addition, compounds were evaluated for inhibition of methamphetamine-evoked endogenous dopamine release by using striatal slices. The most promising compound, UKCP-110, was evaluated for its ability to decrease methamphetamine self-administration and methamphetamine discriminative stimulus cues and for its effect on food-maintained operant responding. UKCP-110, UKCP-111, and UKCP-112 inhibited [(3)H]dihydrotetrabenazine binding (K(i) = 2.66 ± 0.37, 1.05 ± 0.10, and 3.80 ± 0.31 μM, respectively) and had high potency inhibiting [(3)H]dopamine uptake (K(i) = 0.028 ± 0.001, 0.046 ± 0.008, 0.043 ± 0.004 μM, respectively), but lacked affinity at nicotinic receptors. Although the trans-isomers did not alter methamphetamine-evoked dopamine release, UKCP-110 inhibited (IC(50) = 1.8 ± 0.2 μM; I(max) = 67.18 ± 6.11 μM) methamphetamine-evoked dopamine release. At high concentrations, UKCP-110 also increased extracellular dihydroxyphenylacetic acid. It is noteworthy that UKCP-110 decreased the number of methamphetamine self-infusions, while having no effect on food-reinforced behavior or the methamphetamine stimulus cue. Thus, UKCP-110 represents a new lead in the development of novel pharmacotherapies for the treatment of methamphetamine abuse.

Publication types

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

MeSH terms

  • 3,4-Dihydroxyphenylacetic Acid / metabolism
  • Aconitine / analogs & derivatives
  • Aconitine / metabolism
  • Amphetamine-Related Disorders / drug therapy*
  • Animals
  • Behavior, Animal / drug effects
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism
  • Conditioning, Operant
  • Corpus Striatum / cytology
  • Corpus Striatum / drug effects
  • Corpus Striatum / metabolism
  • Dopamine / metabolism*
  • Drug Tolerance
  • Lobeline / analogs & derivatives*
  • Lobeline / metabolism
  • Lobeline / pharmacology*
  • Male
  • Methamphetamine / administration & dosage
  • Methamphetamine / pharmacology*
  • Nicotine / metabolism
  • Protein Binding / drug effects
  • Pyrrolidines / metabolism
  • Pyrrolidines / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Nicotinic / metabolism
  • Reinforcement, Psychology
  • Self Administration
  • Synaptic Vesicles / drug effects
  • Synaptic Vesicles / metabolism
  • Tetrabenazine / analogs & derivatives
  • Tetrabenazine / metabolism
  • Vesicular Monoamine Transport Proteins / antagonists & inhibitors*
  • Vesicular Monoamine Transport Proteins / metabolism

Substances

  • 2,5-di-(2-phenethyl)pyrrolidine
  • Pyrrolidines
  • Receptors, Nicotinic
  • Slc18a2 protein, rat
  • Vesicular Monoamine Transport Proteins
  • 3,4-Dihydroxyphenylacetic Acid
  • methyllycaconitine
  • Methamphetamine
  • Nicotine
  • Lobeline
  • Dopamine
  • Aconitine
  • Tetrabenazine