Maria Lavinia Bartolucci1, Ida Marini1, Francesco Bortolotti1, Daniela Impellizzeri2, Rosanna Di Paola2, Giuseppe Bruschetta2, Rosalia Crupi2, Marco Portelli3, Angela Militi3, Giacomo Oteri3, Emanuela Esposito2, Salvatore Cuzzocrea4,5. 1. Section of Orthodontics, Department of Biomedical Sciences, University of Bologna, Via San Vitale 59, 40125, Bologna, Italy. 2. Department of Chemical, Biological, Pharmaceutical and Environmental Science, University of Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166, Messina, Italy. 3. Department of Biomedical, Dental Science and Morphological and Functional Images, Dental School, 98125, Messina, Italy. 4. Department of Chemical, Biological, Pharmaceutical and Environmental Science, University of Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166, Messina, Italy. salvator@unime.it. 5. Department of Pharmacological and Physiological Sciences, Saint Louis University, School of Medicine, 1402 South Grand Blvd, St. Louis, MO, 63104, USA. salvator@unime.it.
Abstract
OBJECTIVE AND DESIGN: Temporomandibular disorder (TMD) is a common painful condition in the temporomandibular joint (TMJ). Joint inflammation is believed to be a chief cause of pain in patients with TMD, through the release of pro-inflammatory cytokines that induce peripheral sensitization of nerve terminals followed by microglial stimulation. MATERIALS AND SUBJECT: TMJ was induced in rats with the injection of complete Freund's adjuvant (CFA) emulsion into the left TMJ capsule. TREATMENT: The present study would assess the effects of micronized palmitoylethanolamide (m-PEA) on glial activation and trigeminal hypersensitivity. METHODS: Ten mg/kg m-PEA or corresponding vehicle was administered 1 h after CFA and mechanical allodynia and edema were evaluated at 24 and 72 h after CFA injection. RESULTS: CFA-injected animals showed TMJ edema and ipsilateral mechanical allodynia accompanied by a robust growth in GFAP protein-positive satellite glial cells and activation of resident macrophages in the TG. Moreover, m-PEA administration significantly reduced the degree of TMJ damage and pain, macrophage activation in TG and up-regulation of Iba1. CONCLUSIONS: The results confirm that m-PEA could represent a novel approach for monitoring pain during trigeminal nerve sensitization.
OBJECTIVE AND DESIGN:Temporomandibular disorder (TMD) is a common painful condition in the temporomandibular joint (TMJ). Joint inflammation is believed to be a chief cause of pain in patients with TMD, through the release of pro-inflammatory cytokines that induce peripheral sensitization of nerve terminals followed by microglial stimulation. MATERIALS AND SUBJECT: TMJ was induced in rats with the injection of complete Freund's adjuvant (CFA) emulsion into the left TMJ capsule. TREATMENT: The present study would assess the effects of micronized palmitoylethanolamide (m-PEA) on glial activation and trigeminal hypersensitivity. METHODS: Ten mg/kg m-PEA or corresponding vehicle was administered 1 h after CFA and mechanical allodynia and edema were evaluated at 24 and 72 h after CFA injection. RESULTS: CFA-injected animals showed TMJ edema and ipsilateral mechanical allodynia accompanied by a robust growth in GFAP protein-positive satellite glial cells and activation of resident macrophages in the TG. Moreover, m-PEA administration significantly reduced the degree of TMJ damage and pain, macrophage activation in TG and up-regulation of Iba1. CONCLUSIONS: The results confirm that m-PEA could represent a novel approach for monitoring pain during trigeminal nerve sensitization.
Authors: Robert H Dworkin; Alec B O'Connor; Joseph Audette; Ralf Baron; Geoffrey K Gourlay; Maija L Haanpää; Joel L Kent; Elliot J Krane; Alyssa A Lebel; Robert M Levy; Sean C Mackey; John Mayer; Christine Miaskowski; Srinivasa N Raja; Andrew S C Rice; Kenneth E Schmader; Brett Stacey; Steven Stanos; Rolf-Detlef Treede; Dennis C Turk; Gary A Walco; Christopher D Wells Journal: Mayo Clin Proc Date: 2010-03 Impact factor: 7.616
Authors: Leonardo Guasti; Denise Richardson; Maulik Jhaveri; Khalil Eldeeb; David Barrett; Maurice R Elphick; Stephen P H Alexander; David Kendall; Gregory J Michael; Victoria Chapman Journal: Mol Pain Date: 2009-07-01 Impact factor: 3.395