Comparison of the spinal anti-nociceptive effects of ES-242-1 and MK-801, two different NMDA antagonists, in rats.

Abstract

The purpose of this study was to determine whether ES-242-1, a novel N-methyl-D-aspartate (NMDA) receptor antagonist of microbial origin, has anti-nociception at the spinal level and to evaluate how its anti-nociceptive effect differs from that of MK-801, a non-competitive NMDA receptor antagonist. Agents were injected intrathecally (0.1, 1.0 and 10 microg) through a previously implanted PE tube in rats. Formalin (2%, 100 microl) was injected subcutaneously into the left hindpaw 15 min after each antagonist administration. Licking time as a nociceptive behavior was measured in three stages after formalin-injection, such as early phase (0-9 min), late first phase (10-29 min) and late second phase (30-60 min). In the early phase, the largest dose of ES-242-1 significantly decreased total licking time, although MK-801 did not show any significant reduction. With the treatment of 1.0 and 10 microg MK-801, total licking time in both late first and second phases was significantly suppressed, although the smallest dose (0.1 microg) of ES-242-1 showed a significant reduction in the late second phase. These results indicate that ES-242-1 is highly effective against tonic pain, such as inflammatory pain.

• Authors: F Hamada, H Noutsuka, Y Hamada, H Goto
• Journal: Neuroscience research (Neurosci Res) Vol. 40 Issue 1 Pg. 61-6 (May 2001) ISSN: 0168-0102 [Print] Ireland
• PMID: 11311406 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Excitatory Amino Acid Antagonists
• Pyrans
• Receptors, N-Methyl-D-Aspartate
• ES 242-1
• Dizocilpine Maleate

Topics

• Animals
• Dizocilpine Maleate (pharmacology)
• Dose-Response Relationship, Drug
• Excitatory Amino Acid Antagonists (pharmacology)
• Injections, Spinal
• Male
• Nociceptors (drug effects, metabolism)
• Pain (drug therapy, metabolism, physiopathology)
• Pain Measurement (drug effects)
• Pain Threshold (drug effects, physiology)
• Pyrans (pharmacology)
• Rats
• Rats, Sprague-Dawley
• Receptors, N-Methyl-D-Aspartate (antagonists & inhibitors, metabolism)
• Spinal Cord (drug effects, metabolism)
• Time Factors