Mechanical allodynia in rats is blocked by a Ca2+ permeable AMPA receptor antagonist.

Abstract

Mild thermal injury to the hindpaw induces tactile allodynia distal to the injury. The allodynia is blocked by non-NMDA, but not NMDA, antagonists. The calcium permeable subtype of non-NMDA receptors is blocked by Joro spider toxin (JSTX). We injected JSTX or saline intrathecally followed after 5 min, 6 or 24 h by thermal injury. Rats receiving saline had decreased mechanical thresholds. Rats receiving 3 microg JSTX 5 min or 6 h prior to burn showed no allodynia. JSTX had no prominent side effects at doses between 1 and 5 microg. JSTX (5 microg) had no effect on thermal threshold. These results are consistent with the hypothesis that spinal mechanisms leading to tactile allodynia in this injury model act via a calcium permeable AMPA linkage.

• Authors: L S Sorkin, T L Yaksh, C M Doom
• Journal: Neuroreport (Neuroreport) Vol. 10 Issue 17 Pg. 3523-6 (Nov 26 1999) ISSN: 0959-4965 [Print] England
• PMID: 10619637 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• JSTX spider toxin
• Receptors, AMPA
• Receptors, N-Methyl-D-Aspartate
• Spider Venoms
• Calcium

Topics

• Animals
• Burns (physiopathology)
• Calcium (metabolism)
• Cell Membrane Permeability (drug effects)
• Dose-Response Relationship, Drug
• Hair
• Hindlimb
• Hot Temperature
• Male
• Pain (drug therapy, physiopathology)
• Pain Threshold (drug effects)
• Physical Stimulation
• Rats
• Rats, Sprague-Dawley
• Reaction Time
• Receptors, AMPA (antagonists & inhibitors, metabolism)
• Receptors, N-Methyl-D-Aspartate (antagonists & inhibitors, physiology)
• Reflex (drug effects, physiology)
• Respiration (drug effects)
• Spider Venoms (pharmacology)
• Time Factors
• Touch (drug effects, physiology)