title: Receptor specificity defines algogenic properties of propofol and fospropofol.
abstract: BACKGROUND
  Propofol-evoked injection site pain is not observed with fospropofol. We hypothesized that unlike propofol, fospropofol does not activate the irritant receptor, transient receptor potential 1 (TRPA1).
  
  
  METHODS
  We tested the hypothesis using electrophysiology and behavioral studies.
  
  
  RESULTS
  Our data demonstrate that propofol (100 μM) evokes an inward current only in TRPA1-expressing neurons. However, fospropofol (100 μM and 1 mM) is unable to evoke depolarizing currents in either TRPA1-positive or TRPA1-negative neurons. Both propofol and fospropofol produced general anesthesia.
  
  
  CONCLUSIONS
  The lack of algogenic activity in fospropofol is most likely the result of its inability to activate TRPA1 on nociceptors.
authors.affiliation: Department of Anesthesiology, University of Arizona Health Sciences Center, Tucson, AZ 85724, USA.
authors.forename: Amol
authors.initials: A
authors.lastname: Patwardhan
authors.forename: Rebecca
authors.initials: R
authors.lastname: Edelmayer
authors.forename: Emil
authors.initials: E
authors.lastname: Annabi
authors.forename: Theodore
authors.initials: T
authors.lastname: Price
authors.forename: Phil
authors.initials: P
authors.lastname: Malan
authors.forename: Gregory
authors.initials: G
authors.lastname: Dussor
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D006993:Hypnotics and Sedatives / Q000008:administration & dosage* / Q000009:adverse effects; D007275:Injections, Intravenous; D008297:Male; D010146:Pain / Q000139:chemically induced / Q000378:metabolism*; D011355:Prodrugs / Q000008:administration & dosage / Q000009:adverse effects; D015742:Propofol / Q000008:administration & dosage* / Q000009:adverse effects / Q000031:analogs & derivatives*; D051381:Rats; D017207:Rats, Sprague-Dawley; D000074025:TRPA1 Cation Channel; D050052:TRPC Cation Channels / Q000819:agonists / Q000096:biosynthesis*
chemical_list: D006993:Hypnotics and Sedatives; D011355:Prodrugs; D000074025:TRPA1 Cation Channel; D050052:TRPC Cation Channels; C480976:Trpa1 protein, rat; C472965:fospropofol; D015742:Propofol