title: Antiallodynic effect through spinal endothelin-B receptor antagonism in rat models of complex regional pain syndrome.
abstract: Complex regional pain syndrome (CRPS) is a very complicated chronic pain disorder that has been classified into two types (I and II). Endothelin (ET) receptors are involved in pain conditions at the spinal level. We investigated the role of spinal ET receptors in CRPS. Chronic post-ischemia pain (CPIP) was induced in male Sprague-Dawley rats as a model for CRPS-I by placing a tourniquet (O-ring) at the ankle joint for 3h, and removing it to allow reperfusion. Ligation of L5 and L6 spinal nerves to induce neuropathic pain was performed as a model for CRPS-II. After O-ring application and spinal nerve ligation, the paw withdrawal threshold was significantly decreased at injured sites. Intrathecal administration of the selective ET-B receptor antagonist BQ 788 dose-dependently increased the withdrawal threshold in both CRPS-I and CRPS-II. In contrast, ET-A receptor antagonist BQ 123 did not affect the withdrawal threshold in either CRPS type. The ET-1 levels of plasma and spinal cord increased in both CRPS types. Intrathecal BQ 788 decreased the spinal ET-1 level. These results suggest that ET-1 is involved in the development of mechanical allodynia in CRPS. Furthermore, the ET-B receptor appears to be involved in spinal cord-related CRPS.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chonnam National University, Medical School, Gwangju, South Korea.
authors.forename: Yeo Ok
authors.initials: YO
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chonnam National University, Medical School, Gwangju, South Korea.
authors.forename: In Ji
authors.initials: IJ
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chonnam National University, Medical School, Gwangju, South Korea; Center for Creative Biomedical Scientists at Chonnam National University, Gwangju, South Korea. Electronic address: mhyoon@chonnam.ac.kr.
authors.forename: Myung Ha
authors.initials: MH
authors.lastname: Yoon
mesh_terms: D000818:Animals; D002422:Causalgia / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D065131:Endothelin B Receptor Antagonists / Q000494:pharmacology / Q000627:therapeutic use*; D019332:Endothelin-1 / Q000378:metabolism; D006930:Hyperalgesia / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D009842:Oligopeptides / Q000627:therapeutic use; D017288:Pain Threshold / Q000187:drug effects; D010456:Peptides, Cyclic / Q000627:therapeutic use; D010812:Physical Stimulation; D010880:Piperidines / Q000627:therapeutic use; D017207:Rats, Sprague-Dawley; D012018:Reflex / Q000187:drug effects; D012019:Reflex Sympathetic Dystrophy / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D013116:Spinal Cord / Q000378:metabolism; D014110:Touch
chemical_list: D065131:Endothelin B Receptor Antagonists; D019332:Endothelin-1; D009842:Oligopeptides; D010456:Peptides, Cyclic; D010880:Piperidines; C086539:BQ 788; C072247:cyclo(Trp-Asp-Pro-Val-Leu)
keywords: Allodynia; CRPS; ET-B receptor; Endothelin(ET)-1; Spinal cord