Central metabotropic glutamate receptors differentially participate in interleukin-1beta-induced mechanical allodynia in the orofacial area of conscious rats.

Abstract

UNLABELLED:

The present study investigated the role of central metabotropic glutamate receptors (mGluRs) in interleukin-1beta (IL-1beta)-induced mechanical allodynia and mirror-image mechanical allodynia in the orofacial area. Experiments were carried out on male Sprague-Dawley rats weighing 230 to 280 g. After administration of 0.01, 0.1, 1, or 10 pg of IL-1beta into a subcutaneous area of the vibrissa pad, we examined the withdrawal behavioral responses produced by 10 successive trials of an air-puff ramp pressure applied ipsilaterally or contralaterally to the IL-1beta injection site. Subcutaneous injection of IL-1beta produced mechanical allodynia and mirror-image mechanical allodynia in the orofacial area. Intracisternal administration of CPCCOEt, a mGluR1 antagonist, or MPEP, a mGluR5 antagonist, reduced IL-1beta-induced mechanical allodynia and mirror-image mechanical allodynia. Intracisternal administration of APDC, a group II mGluR agonist, or L-AP4, a group III mGluR agonist, reduced both IL-1beta-induced mechanical allodynia and mirror-image mechanical allodynia. The antiallodynic effect, induced by APDC or L-AP4, was blocked by intracisternal pretreatment with LY341495, a group II mGluR antagonist, or CPPG, a group III mGluR antagonist. These results suggest that groups I, II, and III mGluRs differentially modulated IL-1beta-induced mechanical allodynia, as well as mirror-image mechanical allodynia, in the orofacial area.

PERSPECTIVE:

Central group I mGluR antagonists and groups II and III mGluR agonists modulate IL-1beta-induced mechanical allodynia and mirror-image mechanical allodynia in the orofacial area. Therefore, the central application of group I mGluR antagonists or groups II and III mGluR agonists might be of therapeutic value in treating pain disorder.

• Authors: Chang Y Jung, Hyo S Choi, Jin S Ju, Hyo S Park, Tae G Kwon, Yong C Bae, Dong K Ahn
• Journal: The journal of pain (J Pain) Vol. 7 Issue 10 Pg. 747-56 (Oct 2006) ISSN: 1526-5900 [Print] United States
• PMID: 17018335 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Excitatory Amino Acid Agonists
• Excitatory Amino Acid Antagonists
• Interleukin-1beta
• Receptors, Metabotropic Glutamate
• Glutamic Acid

Topics

• Afferent Pathways (drug effects, metabolism)
• Animals
• Disease Models, Animal
• Excitatory Amino Acid Agonists (pharmacology)
• Excitatory Amino Acid Antagonists (pharmacology)
• Facial Pain (chemically induced, metabolism, physiopathology)
• Glutamic Acid (metabolism)
• Hyperalgesia (chemically induced, metabolism, physiopathology)
• Interleukin-1beta (metabolism, pharmacology)
• Male
• Nociceptors (drug effects, metabolism)
• Pain Threshold (drug effects, physiology)
• Rats
• Rats, Sprague-Dawley
• Reaction Time (drug effects, physiology)
• Receptors, Metabotropic Glutamate (drug effects, metabolism)
• Sensory Receptor Cells (drug effects, metabolism)
• Synaptic Transmission (drug effects, physiology)
• Vibrissae (drug effects)