Pharmacological evaluation of SN79, a sigma (σ) receptor ligand, against methamphetamine-induced neurotoxicity in vivo

Eur Neuropsychopharmacol. 2013 Aug;23(8):960-71. doi: 10.1016/j.euroneuro.2012.08.005. Epub 2012 Aug 24.

Abstract

Methamphetamine is a highly addictive psychostimulant drug of abuse, causing hyperthermia and neurotoxicity at high doses. Currently, there is no clinically proven pharmacotherapy to treat these effects of methamphetamine, necessitating identification of potential novel therapeutic targets. Earlier studies showed that methamphetamine binds to sigma (σ) receptors in the brain at physiologically relevant concentrations, where it "acts in part as an agonist." SN79 (6-acetyl-3-(4-(4-(4-florophenyl)piperazin-1-yl)butyl)benzo[d]oxazol-2(3H)-one) was synthesized as a putative σ receptor antagonist with nanomolar affinity and selectivity for σ receptors over 57 other binding sites. SN79 pretreatment afforded protection against methamphetamine-induced hyperthermia and striatal dopaminergic and serotonergic neurotoxicity in male, Swiss Webster mice (measured as depletions in striatal dopamine and serotonin levels, and reductions in striatal dopamine and serotonin transporter expression levels). In contrast, di-o-tolylguanidine (DTG), a well established σ receptor agonist, increased the lethal effects of methamphetamine, although it did not further exacerbate methamphetamine-induced hyperthermia. Together, the data implicate σ receptors in the direct modulation of some effects of methamphetamine such as lethality, while having a modulatory role which can mitigate other methamphetamine-induced effects such as hyperthermia and neurotoxicity.

Keywords: Dopamine; Hyperthermia; Methamphetamine; Neurotoxicity; Serotonin; Sigma receptors.

Publication types

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

MeSH terms

  • Animals
  • Benzoxazoles / adverse effects
  • Benzoxazoles / therapeutic use*
  • Central Nervous System Stimulants / antagonists & inhibitors
  • Central Nervous System Stimulants / toxicity*
  • Corpus Striatum / drug effects
  • Corpus Striatum / metabolism
  • Corpus Striatum / pathology
  • Dopamine / chemistry
  • Dopamine / metabolism
  • Dopamine Antagonists / adverse effects
  • Dopamine Antagonists / therapeutic use
  • Dopamine Plasma Membrane Transport Proteins / antagonists & inhibitors
  • Dopamine Plasma Membrane Transport Proteins / metabolism
  • Drug Synergism
  • Fever / etiology
  • Fever / prevention & control
  • Guanidines / adverse effects
  • Guanidines / therapeutic use
  • Male
  • Methamphetamine / antagonists & inhibitors
  • Methamphetamine / toxicity*
  • Mice
  • Nerve Tissue Proteins / agonists
  • Nerve Tissue Proteins / antagonists & inhibitors*
  • Neurons / drug effects
  • Neurons / metabolism
  • Neurons / pathology
  • Neuroprotective Agents / adverse effects
  • Neuroprotective Agents / therapeutic use*
  • Neurotoxicity Syndromes / metabolism
  • Neurotoxicity Syndromes / pathology
  • Neurotoxicity Syndromes / physiopathology
  • Neurotoxicity Syndromes / prevention & control*
  • Piperazines / adverse effects
  • Piperazines / therapeutic use*
  • Random Allocation
  • Receptors, sigma / agonists
  • Receptors, sigma / antagonists & inhibitors*
  • Serotonin / chemistry
  • Serotonin / metabolism
  • Serotonin Antagonists / adverse effects
  • Serotonin Antagonists / therapeutic use
  • Serotonin Plasma Membrane Transport Proteins / chemistry
  • Serotonin Plasma Membrane Transport Proteins / metabolism

Substances

  • 6-acetyl-3-(4-(4-(4-fluorophenyl)piperazin-1-yl)butyl)benzo(d)oxazol-2(3H)-one
  • Benzoxazoles
  • Central Nervous System Stimulants
  • Dopamine Antagonists
  • Dopamine Plasma Membrane Transport Proteins
  • Guanidines
  • Nerve Tissue Proteins
  • Neuroprotective Agents
  • Piperazines
  • Receptors, sigma
  • Serotonin Antagonists
  • Serotonin Plasma Membrane Transport Proteins
  • Slc6a3 protein, mouse
  • Slc6a4 protein, mouse
  • Serotonin
  • Methamphetamine
  • 1,3-ditolylguanidine
  • Dopamine