title: Antitussive activity of iodo-resiniferatoxin in guinea pigs.
abstract: BACKGROUND
  Iodo-resiniferatoxin (I-RTX) has recently been described as an ultra potent antagonist of the transient receptor potential vanilloid-1 (TRPV1).
  
  
  METHODS
  The ability of I-RTX to inhibit cough induced by inhalation of two putative TRPV1 stimulants (capsaicin and citric acid) was tested in non-anaesthetised guinea pigs.
  
  
  RESULTS
  Pretreatment with I-RTX either intraperitoneally (0.03-0.3 micromol/kg) or by aerosol (0.1-3 microM) reduced the number of coughs produced by inhalation of citric acid (0.25 M) and capsaicin (30 microM) in a dose dependent manner. Capsazepine (CPZ) also reduced citric acid and capsaicin induced cough, but the activity of I-RTX was 10-100 times more potent than CPZ in all the experimental conditions tested.
  
  
  CONCLUSIONS
  I-RTX is a novel and potent antitussive drug which inhibits cough mediated by agents possibly acting via TRPV1 activation.
authors.affiliation: Center of Excellence for the Study of Inflammation, University of Ferrara, Ferrara, Italy. tvm@unife.it
authors.forename: M
authors.initials: M
authors.lastname: Trevisani
authors.forename: A
authors.initials: A
authors.lastname: Milan
authors.forename: R
authors.initials: R
authors.lastname: Gatti
authors.forename: A
authors.initials: A
authors.lastname: Zanasi
authors.forename: S
authors.initials: S
authors.lastname: Harrison
authors.forename: G
authors.initials: G
authors.lastname: Fontana
authors.forename: A H
authors.initials: AH
authors.lastname: Morice
authors.forename: P
authors.initials: P
authors.lastname: Geppetti
mesh_terms: D000818:Animals; D000996:Antitussive Agents / Q000627:therapeutic use*; D003371:Cough / Q000517:prevention & control*; D004224:Diterpenes / Q000627:therapeutic use*; D006168:Guinea Pigs; D007473:Ion Channels; D008297:Male; D011955:Receptors, Drug / Q000037:antagonists & inhibitors*; D050916:TRPV Cation Channels
chemical_list: D000996:Antitussive Agents; D004224:Diterpenes; D007473:Ion Channels; D011955:Receptors, Drug; D050916:TRPV Cation Channels; C476722:Trpv2 protein, rat; C468130:iodoresiniferatoxin