title: The effect of menthol vapor on nasal sensitivity to chemical irritation.
abstract: BACKGROUND
  Among other effects, menthol added to cigarettes may modulate sensory response to cigarette smoke either by masking "harshness" or contributing to a desirable "impact." However, harshness and impact have been imprecisely defined and assessed using subjective measures. Thus, the current experiments used an objective measure of sensitivity to chemical irritation in the nose to test the hypothesis that menthol vapor modulates sensitivity to chemical irritation in the airways.
  
  
  METHODS
  Nasal irritation thresholds were measured for 2 model compounds (acetic acid and allyl isothiocyanate) using nasal lateralization. In this technique, participants simultaneously sniff clean air in one nostril and chemical vapor in the other and attempt to identify the stimulated nostril. People cannot lateralize based on smell alone but can do so when chemicals are strong enough to feel. In one condition, participants were pretreated by sniffing menthol vapor. In a control condition, participants were pretreated by sniffing an odorless blank (within-subjects design).
  
  
  RESULTS
  Pretreatment with menthol vapor decreased sensitivity to nasal irritation from acetic acid (participants required higher concentrations to lateralize) but increased sensitivity to allyl isothiocyanate (lower concentrations were required).
  
  
  CONCLUSIONS
  The current experiments provide objective evidence that menthol vapor can modulate sensitivity to chemical irritation in the upper airways in humans. Cigarette smoke is a complex mixture of chemicals and particulates, and further work will be needed to determine exactly how menthol modulates smoking sensation. A better understanding could lead to treatments tailored to help menthol smokers quit by replacing the sensation of mentholated cigarettes.
authors.affiliation: Monell Chemical Senses Center, Philadelphia, PA 19104, USA. pwise@monell.org
authors.forename: Paul M
authors.initials: PM
authors.lastname: Wise
authors.forename: George
authors.initials: G
authors.lastname: Preti
authors.forename: Jason
authors.initials: J
authors.lastname: Eades
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Wysocki
mesh_terms: D019342:Acetic Acid / Q000008:administration & dosage / Q000494:pharmacology; D000280:Administration, Inhalation; D000328:Adult; D005260:Female; D006801:Humans; D007509:Irritants / Q000494:pharmacology*; D017879:Isothiocyanates / Q000494:pharmacology; D008297:Male; D008610:Menthol / Q000008:administration & dosage / Q000494:pharmacology*; D008875:Middle Aged; D009297:Nasal Mucosa / Q000187:drug effects* / Q000502:physiology; D012677:Sensation / Q000187:drug effects* / Q000502:physiology; D012684:Sensory Thresholds / Q000502:physiology; D012907:Smoking / Q000523:psychology; D013268:Stimulation, Chemical; D014028:Tobacco Smoke Pollution; D055815:Young Adult
chemical_list: D007509:Irritants; D017879:Isothiocyanates; D014028:Tobacco Smoke Pollution; D008610:Menthol; C004471:allyl isothiocyanate; D019342:Acetic Acid