title: Comparable effects of capsaicin-containing red pepper sauce and hydrochloric acid on secondary peristalsis in humans.
abstract: OBJECTIVE
  We aimed to evaluate whether acute esophageal instillation of capsaicin and hydrochloric acid had different effects on distension-induced secondary peristalsis.
  
  
  METHODS
  Secondary peristalsis was induced by slow and rapid air injections into the mid-esophagus after the evaluation of baseline motility in 16 healthy subjects. The effects on secondary peristalsis were determined by esophageal instillation with capsaicin-containing red pepper sauce (pure capsaicin, 0.84 mg) and hydrochloric acid (0.1 N).
  
  
  RESULTS
  The administration of capsaicin induced a significant increase in the visual analogue scale score for heartburn as compared with hydrochloric acid (P = 0.002). The threshold volume for generating secondary peristalsis during slow and rapid air distensions did not differ between capsaicin and hydrochloric acid infusions. Hydrochloric acid significantly increased the frequency of secondary peristalsis in response to rapid air distension compared with capsaicin infusion (P = 0.03). Pressure wave amplitude during slow air distension was greater with the infusion of hydrochloric acid than capsaicin infusion (P = 0.001). The pressure wave duration during rapid air distension was longer after capsaicin infusion than hydrochloric acid infusion (P = 0.01). The pressure wave amplitude during rapid air distension was similar between capsaicin and hydrochloric acid infusions.
  
  
  CONCLUSIONS
  Despite subtle differences in physiological characteristics of secondary peristalsis, acute esophageal instillation of capsaicin and hydrochloric acid produced comparable effects on distension-induced secondary peristalsis. Our data suggest the coexistence of both acid- and capsaicin-sensitive afferents in human esophagus which produce similar physiological alterations in secondary peristalsis.
authors.affiliation: Department of Medicine, Buddhist Tzu Chi General Hospital and Tzu Chi University, Hualien, Taiwan.
authors.forename: Chien-Lin
authors.initials: CL
authors.lastname: Chen
authors.forename: Chih-Hsun
authors.initials: CH
authors.lastname: Yi
authors.forename: Tso-Tsai
authors.initials: TT
authors.lastname: Liu
mesh_terms: D000328:Adult; D002211:Capsaicin / Q000009:adverse effects / Q000494:pharmacology*; D002212:Capsicum; D004947:Esophagus / Q000502:physiology*; D005260:Female; D006356:Heartburn / Q000139:chemically induced / Q000503:physiopathology; D006801:Humans; D006851:Hydrochloric Acid / Q000009:adverse effects / Q000494:pharmacology*; D008297:Male; D008365:Manometry; D010528:Peristalsis / Q000187:drug effects* / Q000502:physiology; D055815:Young Adult
chemical_list: D006851:Hydrochloric Acid; D002211:Capsaicin
keywords: capsaicin; esophageal motility; hydrochloric acid; secondary peristalsis