title: Capsaicin sensitive afferents mediate the development of heat hyperalgesia and hindpaw edema after sciatic section in rats.
abstract: Sciatic section in rats evokes chronic hyperalgesia, autotomy pain behavior, and hindpaw edema, a constellation resembling complex regional pain syndrome (CRPS) in man. Glucocorticoid treatment inhibits these sequelae of sciatic section and also blocks neurogenic extravasation. Small diameter afferent neurons release substance P (SP), a mediator of both hyperalgesia and neurogenic extravasation. Now, we show that pre-emptive destruction of the small diameter fibers prevents neurogenic extravasation, and prevented the development of heat hyperalgesia and hindpaw edema after sciatic section. Thus, capsaicin sensitive primary afferent neurons which release SP are required for the development of heat hyperalgesia and hindpaw edema in this animal model of CRPS.
authors.affiliation: Department of Functional Restoration, Stanford University School of Medicine, Stanford, CA, USA. wkingery@stanford.edu
authors.forename: Wade S
authors.initials: WS
authors.lastname: Kingery
authors.forename: Geeta S
authors.initials: GS
authors.lastname: Agashe
authors.forename: Tian Zhi
authors.initials: TZ
authors.lastname: Guo
authors.forename: M Frances
authors.initials: MF
authors.lastname: Davies
authors.forename: J David
authors.initials: JD
authors.lastname: Clark
authors.forename: Mervyn
authors.initials: M
authors.lastname: Maze
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002211:Capsaicin / Q000494:pharmacology*; D004396:Coloring Agents / Q000493:pharmacokinetics; D020918:Complex Regional Pain Syndromes / Q000503:physiopathology; D003714:Denervation; D004195:Disease Models, Animal; D004487:Edema / Q000503:physiopathology*; D004558:Electric Stimulation; D006614:Hindlimb; D006930:Hyperalgesia / Q000503:physiopathology*; D008297:Male; D009475:Neurons, Afferent / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000502:physiology* / Q000601:surgery
chemical_list: D004396:Coloring Agents; D002211:Capsaicin