title: Development and characterization of a novel, anatomically relevant rat model of acute postoperative pain.
abstract: Acute postoperative pain remains a significant health care issue. Development of anatomically relevant animal models of postoperative pain, with improved predictive validity, would advance understanding of postoperative pain mechanisms and improve treatment outcomes. This study aimed to develop, characterize, and validate a rat model of acute postoperative pain associated with inguinal hernia repair based on the Lichtenstein inguinal hernia repair procedure (without hernia induction). We hypothesized that the surgery would result in reduced spontaneous locomotor activity, which would represent a pain-related phenotype. Postsurgical characterization involved extensive monitoring of home cage and open field locomotor activity, as well as mechanical hypersensitivity and assessment of c-Fos expression in the dorsal horn of the spinal cord. In pharmacologic validation studies, rats received morphine, carprofen, or paracetamol 1 hour before, and/or immediately after, surgery. Rats that underwent hernia repair surgery exhibited significantly lower horizontal and vertical activities in the home cage and open field in the early postsurgical period, compared with sham rats or rats that underwent skin incision only. Morphine, carprofen, and paracetamol attenuated the surgery-induced reductions in locomotor activity, to varying degrees. Surgery was associated with significantly increased c-Fos expression in the ipsilateral dorsal horn of the spinal cord, an effect attenuated by carprofen treatment. These results support the development and characterization of a novel, anatomically relevant animal model of acute postoperative pain that may facilitate development of improved treatment regimens.
  
  
  CONCLUSIONS
  Acute pain following inguinal hernia repair can be difficult to treat. Here we report, for the first time, the development of a novel, anatomically relevant rat model to facilitate improved understanding and treatment of acute postoperative pain following inguinal hernia repair.
authors: Discipline of Pharmacology and Therapeutics, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland; Discipline of Physiology, School of Medicine, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland; Galway Neuroscience Centre and Centre for Pain Research, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland.
authors: Dara
authors: D
authors: Bree
authors: Discipline of Pharmacology and Therapeutics, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland; Discipline of Physiology, School of Medicine, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland; Galway Neuroscience Centre and Centre for Pain Research, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland; Research and Development, Covidien, North Haven, Connecticut.
authors: Orla
authors: O
authors: Moriarty
authors: Discipline of Pharmacology and Therapeutics, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland; Discipline of Physiology, School of Medicine, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland; Galway Neuroscience Centre and Centre for Pain Research, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland; Research and Development, Covidien, North Haven, Connecticut.
authors: Cliona M
authors: CM
authors: O'Mahony
authors: Discipline of Pharmacology and Therapeutics, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland; Discipline of Physiology, School of Medicine, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland; Galway Neuroscience Centre and Centre for Pain Research, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland.
authors: Bradley
authors: B
authors: Morris
authors: Discipline of Pharmacology and Therapeutics, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland; Galway Neuroscience Centre and Centre for Pain Research, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland.
authors: Karen
authors: K
authors: Bannerton
authors: Research and Development, Covidien, North Haven, Connecticut.
authors: Daniel C
authors: DC
authors: Broom
authors: Discipline of Pharmacology and Therapeutics, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland; Galway Neuroscience Centre and Centre for Pain Research, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland.
authors: John P
authors: JP
authors: Kelly
authors: Discipline of Physiology, School of Medicine, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland; Galway Neuroscience Centre and Centre for Pain Research, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland.
authors: Michelle
authors: M
authors: Roche
authors: Discipline of Pharmacology and Therapeutics, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland; Galway Neuroscience Centre and Centre for Pain Research, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland. Electronic address: david.finn@nuigalway.ie.
authors: David P
authors: DP
authors: Finn
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage / Q000494:pharmacology; D059787:Acute Pain / Q000188:drug therapy / Q000503:physiopathology*; D000700:Analgesics / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D002227:Carbazoles / Q000008:administration & dosage / Q000494:pharmacology; D004195:Disease Models, Animal; D016762:Genes, fos / Q000502:physiology; D006552:Hernia, Inguinal / Q000601:surgery; D059685:Herniorrhaphy; D006930:Hyperalgesia / Q000188:drug therapy / Q000503:physiopathology; D008297:Male; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology*; D009619:Nociceptors / Q000502:physiology; D010149:Postoperative Pain / Q000188:drug therapy / Q000503:physiopathology*; D010641:Phenotype; D051381:Rats; D066148:Spinal Cord Dorsal Horn / Q000378:metabolism*
chemical_list: D000700:Analgesics; D002227:Carbazoles; D000082:Acetaminophen; D009020:Morphine; C007005:carprofen
keywords: Postsurgical pain; behavior; c-Fos; carprofen; hernia repair; locomotor activity; morphine; paracetamol