The mGluR5 selective antagonist 6-methyl-2-(phenylethynyl)-pyridine reduces the spinal neuron pain-related activity in mononeuropathic rats.

Abstract

In rats with chronic constriction of one sciatic nerve (CCI rats), showing behavioural signs of neuropathic pain, 6-methyl-2-(phenylethynyl)-pyridine (MPEP), a selective mGluR5 antagonist, was intraperitoneally administered at 0.75, 1.0 and 1.5 mg/kg or spinally microejected and the effects on the lumbar wide dynamic range neurons activity were investigated. In CCI rats MPEP at 1.0 and 1.5 (but not at 0.75) mg/kg, or spinally microejected induced a significant reduction of the spontaneous (SA) and noxious evoked activity (NEA), and a significant decrease of the suppression of the afterdischarge duration. In sham rats SA was unaffected and NEA was significantly reduced by 1.0 and 1.5 mg/kg MPEP dosages. These findings indicate that the metabotropic GluR5 receptor plays a role in the spinal cord processes underlying neuropathic pain and represents a potential target for new therapeutic approaches.

• Authors: Maria Luisa Sotgiu, Paola Bellomi, Gabriele E M Biella
• Journal: Neuroscience letters (Neurosci Lett) Vol. 342 Issue 1-2 Pg. 85-8 (May 15 2003) ISSN: 0304-3940 [Print] Ireland
• PMID: 12727324 (Publication Type: Journal Article)

Chemical References

• Excitatory Amino Acid Antagonists
• Grm5 protein, rat
• Pyridines
• Receptor, Metabotropic Glutamate 5
• Receptors, Metabotropic Glutamate
• 6-methyl-2-(phenylethynyl)pyridine

Topics

• Action Potentials
• Animals
• Electrophysiology
• Excitatory Amino Acid Antagonists (pharmacology)
• Lumbosacral Region
• Neurons (drug effects)
• Pain (drug therapy, physiopathology)
• Pyridines (pharmacology)
• Rats
• Receptor, Metabotropic Glutamate 5
• Receptors, Metabotropic Glutamate (antagonists & inhibitors, physiology)
• Sciatic Nerve (injuries)
• Spinal Cord (drug effects, physiopathology)