title: Meloxicam prevents COX-2-mediated post-surgical inflammation but not pain following laparotomy in mice.
abstract: BACKGROUND
  Inflammation is thought to be a major contributor to post-surgical pain, so non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used analgesics. However, compared to rats, considerably less is known as to how successfully these prevent pain in mice.
  
  
  METHODS
  A fluorescent COX-2 selective probe was used for the first time to evaluate the post-surgical anti-inflammatory effects of meloxicam, and automated behaviour analyses (HomeCageScan; HCS), the Mouse Grimace Scale (MGS) and body weight changes to assess its pain-preventative properties. Groups of 8-9 BALB/c mice were subcutaneously injected with saline (0.3 mL) or meloxicam at (1, 5 or 20 mg/kg) 1 h before a 1.5-cm midline laparotomy. The probe or a control dye (2 mg/kg) was injected intravenously 3 h later. Imaging was used to quantify inflammation at 7, 24 and 48 h following surgery. HCS data and MGS scores were respectively obtained from video recordings and photographs before surgery and 24 h later.
  
  
  RESULTS
  Post-surgical inflammation was dose dependently reduced by meloxicam; with 5 or 20 mg/kg being most effective compared to saline. However, all mice lost weight, MGS scores increased and behavioural activity was reduced by surgery for at least 24 h with no perceivable beneficial effect of meloxicam on any of these potentially pain-associated changes.
  
  
  CONCLUSIONS
  Although meloxicam prevented inflammation, even large doses did not prevent post-laparotomy pain possibly arising due to a range of factors, including, but not limited to inflammation. MGS scoring can be applied by very naïve assessors and so should be effective for cage-side use.
authors.affiliation: Comparative Biology Centre, The Medical School, University of Newcastle, Newcastle upon Tyne, UK.
authors.forename: J V
authors.initials: JV
authors.lastname: Roughan
authors.affiliation: Comparative Biology Centre, The Medical School, University of Newcastle, Newcastle upon Tyne, UK.
authors.forename: H G M J
authors.initials: HG
authors.lastname: Bertrand
authors.affiliation: Comparative Biology Centre, The Medical School, University of Newcastle, Newcastle upon Tyne, UK.
authors.forename: H M
authors.initials: HM
authors.lastname: Isles
mesh_terms: D000700:Analgesics / Q000627:therapeutic use*; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D007249:Inflammation / Q000188:drug therapy*; D007813:Laparotomy / Q000009:adverse effects*; D008297:Male; D000077239:Meloxicam; D051379:Mice; D010147:Pain Measurement / Q000379:methods; D010149:Postoperative Pain / Q000188:drug therapy*; D013843:Thiazines / Q000627:therapeutic use*; D013844:Thiazoles / Q000627:therapeutic use*
chemical_list: D000700:Analgesics; D000894:Anti-Inflammatory Agents, Non-Steroidal; D013843:Thiazines; D013844:Thiazoles; D000077239:Meloxicam