The selective sigma-1 receptor antagonist E-52862 attenuates neuropathic pain of different aetiology in rats

Sci Rep. 2016 Apr 18:6:24591. doi: 10.1038/srep24591.

Abstract

E-52862 is a selective σ1R antagonist currently undergoing phase II clinical trials for neuropathic pain and represents a potential first-in-class analgesic. Here, we investigated the effect of single and repeated administration of E-52862 on different pain-related behaviours in several neuropathic pain models in rats: mechanical allodynia in cephalic (trigeminal) neuropathic pain following chronic constriction injury of the infraorbital nerve (IoN), mechanical hyperalgesia in streptozotocin (STZ)-induced diabetic polyneuropathy, and cold allodynia in oxaliplatin (OX)-induced polyneuropathy. Mechanical hypersensitivity induced after IoN surgery or STZ administration was reduced by acute treatment with E-52862 and morphine, but not by pregabalin. In the OX model, single administration of E-52862 reversed the hypersensitivity to cold stimuli similarly to 100 mg/kg of gabapentin. Interestingly, repeated E-52862 administration twice daily over 7 days did not induce pharmacodynamic tolerance but an increased antinociceptive effect in all three models. Additionally, as shown in the STZ and OX models, repeated daily treatment with E-52862 attenuated baseline pain behaviours, which supports a sustained modifying effect on underlying pain-generating mechanisms. These preclinical findings support a role for σ1R in neuropathic pain and extend the potential for the use of selective σ1R antagonists (e.g., E-52862) to the chronic treatment of cephalic and extra-cephalic neuropathic pain.

MeSH terms

  • Analgesics / administration & dosage
  • Analgesics / pharmacology
  • Analgesics / therapeutic use*
  • Animals
  • Diabetic Neuropathies / complications
  • Hyperalgesia / drug therapy*
  • Hyperalgesia / etiology
  • Male
  • Morpholines / administration & dosage
  • Morpholines / pharmacology
  • Morpholines / therapeutic use*
  • Neuralgia / drug therapy*
  • Neuralgia / etiology
  • Organoplatinum Compounds / toxicity
  • Oxaliplatin
  • Peripheral Nerve Injuries / complications
  • Pyrazoles / administration & dosage
  • Pyrazoles / pharmacology
  • Pyrazoles / therapeutic use*
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, sigma / antagonists & inhibitors*
  • Sigma-1 Receptor

Substances

  • 4-(2-((5-methyl-1-(2-naphthalenyl)-1H-pyrazol-3-yl)oxy)ethyl)morpholine
  • Analgesics
  • Morpholines
  • Organoplatinum Compounds
  • Pyrazoles
  • Receptors, sigma
  • Oxaliplatin