title: Magnesium sulphate attenuate remifentanil-induced postoperative hyperalgesia via regulating tyrosine phosphorylation of the NR2B subunit of the NMDA receptor in the spinal cord.
abstract: BACKGROUND
  Remifentanil induced hyperalgesia (RIH) is characterized by stimulation evoked pain including allodynia and thermal hyperalgesia after remifentanil infusion. N-methyl-D-aspartate (NMDA) receptor was reported to be involved in the progress of RIH. We hypothesized that intrathecal MgSO4could relieve hyperalgesia after remifentanil infusion via regulating phosphorylation of NMDA receptor NR2B subunit activity in this study.
  
  
  METHODS
  Thirty two rats were randomly allocated into control group, model of RIH group, RIH plus 100ug MgSO4group, RIH plus 300ug MgSO4group. Mechanical and thermal hyperalgesia were tested at -24thh, 2ndh, 6thh, 24thh, 48thh after remifentanil infusion. Following sacrifice of rats after the last behavioral test, we performed the western blot to detect the expression of spinal phosphorylated NMDA receptor NR2B subunit (pNR2B) in the L4-L5segments.
  
  
  RESULTS
  Intrathecal MgSO4(100, 300 μg) dose-dependently reduced thermal and mechanical hyperalgesia from 2 h to 48 h after remifentanil infusion. Remifentanil infusion remarkably stimulated the expression of pNR2B. Nevertheless, the increased amount of pNR2B by RIH was dose-dependently suppressed by intrathecal infusion of MgSO4in rats.
  
  
  CONCLUSIONS
  Remifentanil induced hyperalgesia/allodynia could be ameliorated by Mg-mediated blockade targeting the NR2B subunit in NMDA receptors.
authors.affiliation: Department of Anesthesiology, 1st Affiliated hospital, Soochow University, 188#, Shizi Street, Gusu District, Suzhou, 215000, China.|Department of Anesthesiology, 1st Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
authors.forename: Jiehao
authors.initials: J
authors.lastname: Sun
authors.affiliation: Department of Anesthesiology, 1st Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
authors.forename: Hai
authors.initials: H
authors.lastname: Lin
authors.affiliation: Department of Anesthesiology, 1st Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
authors.forename: Guodong
authors.initials: G
authors.lastname: He
authors.affiliation: Department of Anesthesiology, 1st Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
authors.forename: Wendong
authors.initials: W
authors.lastname: Lin
authors.affiliation: Department of Anesthesiology, 1st Affiliated hospital, Soochow University, 188#, Shizi Street, Gusu District, Suzhou, 215000, China. szyangjp@126.com.
authors.forename: Jianping
authors.initials: J
authors.lastname: Yang
mesh_terms: D000700:Analgesics; D000818:Animals; D006930:Hyperalgesia / Q000139:chemically induced / Q000517:prevention & control*; D006993:Hypnotics and Sedatives / Q000009:adverse effects*; D007278:Injections, Spinal; D008159:Lumbar Vertebrae / Q000378:metabolism; D008278:Magnesium Sulfate / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D010880:Piperidines / Q000009:adverse effects*; D011183:Postoperative Complications / Q000139:chemically induced / Q000517:prevention & control; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000378:metabolism*; D000077208:Remifentanil; D015398:Signal Transduction / Q000187:drug effects; D013116:Spinal Cord / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism
chemical_list: D000700:Analgesics; D006993:Hypnotics and Sedatives; C121001:NR2B NMDA receptor; D010880:Piperidines; D016194:Receptors, N-Methyl-D-Aspartate; D014443:Tyrosine; D008278:Magnesium Sulfate; D000077208:Remifentanil
keywords: Hyperalgesia; Magnesium; NMDA receptor; NR2B; Remifentanil