title: Two TRPV1 receptor antagonists are effective in two different experimental models of migraine.
abstract: BACKGROUND
  The capsaicin and heat responsive ion channel TRPV1 is expressed on trigeminal nociceptive neurons and has been implicated in the pathophysiology of migraine attacks. Here we investigate the efficacy of two TRPV1 channel antagonists in blocking trigeminal activation using two in vivo models of migraine.
  
  
  METHODS
  Male Sprague-Dawley rats were used to study the effects of the TRPV1 antagonists JNJ-38893777 and JNJ-17203212 on trigeminal activation. Expression of the immediate early gene c-fos was measured following intracisternal application of inflammatory soup. In a second model, CGRP release into the external jugular vein was determined following injection of capsaicin into the carotid artery.
  
  
  RESULTS
  Inflammatory up-regulation of c-fos in the trigeminal brain stem complex was dose-dependently and significantly reduced by both TRPV1 antagonists. Capsaicin-induced CGRP release was attenuated by JNJ-38893777 only in higher dosage. JNJ-17203212 was effective in all doses and fully abolished CGRP release in a time and dose-dependent manner.
  
  
  CONCLUSIONS
  Our results describe two TRPV1 antagonists that are effective in two in vivo models of migraine. These results suggest that TRPV1 may play a role in the pathophysiological mechanisms, which are relevant to migraine.
authors.affiliation: Department of Physiology, Uniklinik RWTH Aachen, Pauwelsstr. 30, D-52074, Aachen, Germany, jmeents@ukaachen.de.
authors.forename: Jannis E
authors.initials: JE
authors.lastname: Meents
authors.forename: Jan
authors.initials: J
authors.lastname: Hoffmann
authors.forename: Sandra R
authors.initials: SR
authors.lastname: Chaplan
authors.forename: Lars
authors.initials: L
authors.lastname: Neeb
authors.forename: Sigrid
authors.initials: S
authors.lastname: Schuh-Hofer
authors.forename: Alan
authors.initials: A
authors.lastname: Wickenden
authors.forename: Uwe
authors.initials: U
authors.lastname: Reuter
mesh_terms: D000631:Aminopyridines / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D002211:Capsaicin / Q000633:toxicity; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D016762:Genes, fos / Q000187:drug effects; D008297:Male; D008881:Migraine Disorders / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism; D010879:Piperazines / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D050916:TRPV Cation Channels / Q000037:antagonists & inhibitors*; D016896:Treatment Outcome; D015854:Up-Regulation / Q000187:drug effects
chemical_list: C500065:4-(3-trifluoromethylpyridin-2-yl)piperazine-1-carboxylic acid (5-trifluoromethylpyridin-2-yl)amide; D000631:Aminopyridines; D010879:Piperazines; D050916:TRPV Cation Channels; C494484:TRPV1 receptor; D002211:Capsaicin