title: Ankle joint mobilization affects postoperative pain through peripheral and central adenosine A1 receptors.
abstract: BACKGROUND
  Physical therapists frequently use joint mobilization therapy techniques to treat people with musculoskeletal dysfunction and pain. Several studies suggest that endogenous adenosine may act in an analgesic fashion in various pain states.
  
  
  OBJECTIVE
  The purpose of this study was to investigate the contribution of the adenosinergic system on the antihyperalgesic effect of ankle joint mobilization (AJM).
  
  
  METHODS
  This was a experimental study.
  
  
  METHODS
  To test the hypothesis that the adrenosinergic system is involved in the antihyperalgesic effect of AJM, mice (25-35 g) submitted to plantar incision surgery were used as a model of acute postoperative pain. The mice were subjected to AJM for 9 minutes. Withdrawal frequency to mechanical stimuli was assessed 24 hours after plantar incision surgery and 30 minutes after AJM, adenosine, clonidine, or morphine treatments. The adenosinergic system was assessed by systemic (intraperitoneal), central (intrathecal), and peripheral (intraplantar) administration of caffeine. The participation of the A1 receptor was investigated using a selective adenosine A1 receptor subtype antagonist. In addition, previous data on the involvement of the serotonergic and noradrenergic systems in the antihyperalgesic effect of AJM were confirmed.
  
  
  RESULTS
  Ankle joint mobilization decreased mechanical hyperalgesia, and this effect was reversed by pretreatment of the animals with caffeine given by intraperitoneal, intraplantar, and intrathecal routes. In addition, intraplanar and intrathecal administrations of 1,3-dipropyl-8-cyclopentylxanthine (DPCPX, a selective adenosine A1 subtype receptor antagonist) or systemic administration of yohimbine or ρ-chlorophenylalanine methyl ester hydrochloride (PCPA) blocked the antihyperalgesia induced by AJM.
  
  
  CONCLUSIONS
  The results are limited to animal models and cannot be generalized to acute pain in humans.
  
  
  CONCLUSIONS
  This study demonstrated the involvement of the adenosinergic system in the antihyperalgesic effect of AJM in a rodent model of pain and provides a possible mechanism basis for AJM-induced relief of acute pain.
authors.affiliation: Laboratório de Neurobiologia da Dor e Inflamação, Programa Pós-Graduação em Neurociências, Departamento de Ciências Fisiológicas, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, Florianópolis, Santa Catarina, Brazil. danielmartinsfisio@hotmail.com
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Martins
authors.forename: Leidiane
authors.initials: L
authors.lastname: Mazzardo-Martins
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Cidral-Filho
authors.forename: Juliana
authors.initials: J
authors.lastname: Stramosk
authors.forename: Adair R S
authors.initials: AR
authors.lastname: Santos
mesh_terms: D000241:Adenosine / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D000843:Ankle Joint / Q000503:physiopathology* / Q000601:surgery; D002110:Caffeine / Q000494:pharmacology; D003000:Clonidine / Q000494:pharmacology; D004195:Disease Models, Animal; D010134:Fenclonine / Q000031:analogs & derivatives / Q000494:pharmacology; D006930:Hyperalgesia / Q000517:prevention & control*; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology; D010149:Postoperative Pain / Q000517:prevention & control*; D043682:Receptor, Adenosine A1 / Q000187:drug effects / Q000502:physiology*; D014970:Xanthines / Q000494:pharmacology; D015016:Yohimbine / Q000494:pharmacology
chemical_list: D043682:Receptor, Adenosine A1; D014970:Xanthines; C020261:4-chlorophenylalanine methyl ester; D015016:Yohimbine; D002110:Caffeine; D009020:Morphine; C051360:1,3-dipropyl-8-cyclopentylxanthine; D000241:Adenosine; D003000:Clonidine; D010134:Fenclonine