title: Effects of a 5-HT2A receptor antagonist, sarpogrelate on thermal or inflammatory pain.
abstract: The effects of intrathecally and systemically administered 5-hydroxytriptamine (5-HT)(2A) receptor antagonist, sarpogrelate on acute thermal or formalin induced pain were examined. Male Sprague-Dawley rats with lumbar intrathecal catheters were tested with their tail withdrawal response to thermal stimulation (tail flick test) or their paw flinching and shaking response by subcutaneous formalin injection into the hind paw (formalin test) after intrathecal or intraperitoneal administration of sarpogrelate. 5-HT(2A) receptor agonist was used to antagonize the effects of sarpogrelate. In the tail flick test, only intraperitoneal administration induced analgesia. In the formalin test, both intrathecal and intraperitoneal administration were analgesic. The analgesic effects were inhibited by pretreatment with 5-HT(2A) receptor agonist. Motor disturbance and behavioral side effects were not observed. In conclusion, sarpogrelate might be analgesic on inflammatory induced acute and facilitated pain by intrathecal or systemic administration. However, only systemic administration could be effective on thermal induced acute pain.
authors.affiliation: Department of Anesthesiology, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan. nishit-tky@umin.ac.jp
authors.forename: Tomoki
authors.initials: T
authors.lastname: Nishiyama
mesh_terms: D000700:Analgesics / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006930:Hyperalgesia / Q000188:drug therapy*; D007249:Inflammation / Q000150:complications; D007274:Injections, Intraperitoneal; D007278:Injections, Spinal; D008297:Male; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D010147:Pain Measurement / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D044402:Receptor, Serotonin, 5-HT2A / Q000502:physiology; D012701:Serotonin / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D058830:Serotonin 5-HT2 Receptor Antagonists; D012702:Serotonin Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D017366:Serotonin Receptor Agonists / Q000008:administration & dosage / Q000494:pharmacology; D013386:Succinates / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D000700:Analgesics; D044402:Receptor, Serotonin, 5-HT2A; D058830:Serotonin 5-HT2 Receptor Antagonists; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D013386:Succinates; C064294:sarpogrelate; C042390:alpha-methylserotonin; D012701:Serotonin