title: Local administration of a synthetic cell-penetrating peptide antagonizing TrkA function suppresses inflammatory pain in rats.
abstract: Novel agents that inhibit nerve growth factor signaling are required for the treatment of inflammatory pain. The present study investigated the effect of local administration of inhibitory peptide of TrkA (IPTRK3), a synthetic cell-penetrating peptide that antagonizes TrkA function, in complete Freund's adjuvant (CFA)-induced hyperalgesia in rats. Three hours after subcutaneous injection of CFA into the plantar surface of the rat's left hind paw, 10 mM IPTRK3 was injected at the same site. Thermal and mechanical hyperalgesia were tested in the ipsilateral hind paw until 7 days after CFA injection. The ipsilateral dorsal root ganglion (DRG) was dissected out for immunohistochemical analysis of transient receptor potential vanilloid subfamily member 1 (TRPV1) channels and TrkA. Local injection of this peptide significantly suppressed both thermal and mechanical hyperalgesia produced by CFA and also significantly reduced TRPV1 expression at the DRG. These results suggest that local administration of IPTRK3 is likely effective in the treatment of inflammatory pain in rats.
authors.affiliation: Department of Anesthesiology and Reanimatology, Faculty of Medical Sciences, University of Fukui, Japan.
authors.forename: Koyo
authors.initials: K
authors.lastname: Ueda
authors.forename: Munetaka
authors.initials: M
authors.lastname: Hirose
authors.forename: Eri
authors.initials: E
authors.lastname: Murata
authors.forename: Mayumi
authors.initials: M
authors.lastname: Takatori
authors.forename: Masashi
authors.initials: M
authors.lastname: Ueda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ikeda
authors.forename: Kenji
authors.initials: K
authors.lastname: Shigemi
mesh_terms: D000818:Animals; D005727:Ganglia, Spinal / Q000187:drug effects / Q000378:metabolism; D007150:Immunohistochemistry; D007249:Inflammation / Q000517:prevention & control*; D007279:Injections, Subcutaneous; D008297:Male; D010146:Pain / Q000517:prevention & control*; D010455:Peptides / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020917:Receptor, trkA / Q000037:antagonists & inhibitors*; D050916:TRPV Cation Channels / Q000378:metabolism
chemical_list: C551391:IPTRK3 peptide; D010455:Peptides; D050916:TRPV Cation Channels; C493922:Trpv1 protein, rat; D020917:Receptor, trkA