Format

Send to

Choose Destination
See comment in PubMed Commons below
Pain. 2014 Apr;155(4):723-32. doi: 10.1016/j.pain.2013.12.030. Epub 2014 Jan 7.

Differential regulation of peripheral IL-1β-induced mechanical allodynia and thermal hyperalgesia in rats.

Author information

1
Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea.
2
Department of Pediatric Dentistry, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea.
3
Department of Oral Anatomy, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea.
4
Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea. Electronic address: dkahn@knu.ac.kr.

Abstract

This study examined the differential mechanisms of mechanical allodynia and thermal hyperalgesia after injection of interleukin (IL) 1β into the orofacial area of male Sprague-Dawley rats. The subcutaneous administration of IL-1β produced both mechanical allodynia and thermal hyperalgesia. Although a pretreatment with iodoresiniferatoxin (IRTX), a transient receptor potential vanilloid 1 (TRPV1) antagonist, did not affect IL-1β-induced mechanical allodynia, it significantly abolished IL-1β-induced thermal hyperalgesia. On the other hand, a pretreatment with D-AP5, an N-methyl-d-aspartate (NMDA) receptor antagonist, and NBQX, an α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist, blocked IL-1β-induced mechanical allodynia. Pretreatment with H89, a protein kinase A (PKA) inhibitor, blocked IL-1β-induced mechanical allodynia but not thermal hyperalgesia. In contrast, pretreatment with chelerythrine, a protein kinase C (PKC) inhibitor, inhibited IL-1β-induced thermal hyperalgesia. Subcutaneous injections of 2% lidocaine, a local anesthetic agent, blocked IL-1β-induced thermal hyperalgesia but not IL-1β-induced mechanical allodynia. In the resiniferatoxin (RTX)-pretreated rats, a subcutaneous injection of IL-1β did not produce thermal hyperalgesia due to the depletion of TRPV1 in the primary afferent fibers. Double immunofluorescence revealed the colocalization of PKA with neurofilament 200 (NF200) and of PKC with the calcitonin gene-related peptide (CGRP) in the trigeminal ganglion. Furthermore, NMDA receptor 1 (NR1) and TRPV1 predominantly colocalize with PKA and PKC, respectively, in the trigeminal ganglion. These results suggest that IL-1β-induced mechanical allodynia is mediated by sensitized peripheral NMDA/AMPA receptors through PKA-mediated signaling in the large-diameter primary afferent nerve fibers, whereas IL-1β-induced thermal hyperalgesia is mediated by sensitized peripheral TRPV1 receptors through PKC-mediated signaling in the small-diameter primary afferent nerve fibers.

KEYWORDS:

Air puff; IL-1β; Mechanical allodynia; NMDA; TRPV1; Thermal hyperalgesia

PMID:
24406203
DOI:
10.1016/j.pain.2013.12.030
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Wolters Kluwer
    Loading ...
    Support Center