title: A distinct salivary secretory response mediated by the esophago-salivary reflex in patients with Barrett's esophagus: its potential pathogenetic implications.
abstract: OBJECTIVE
  A significantly compromised epidermal growth factor (EGF) secretion by basal parotid saliva may contribute to the development of Barrett's esophagus (BE). The rate of secretion of EGF as well as a wide spectrum of protective factors in total basal and stimulated saliva in BE patients remains to be explored. We therefore studied the rate of secretion of salivary buffers, glycoconjugate, protein, EGF, transforming growth factor α (TGFα) and prostaglandin E₂ (PGE₂), evoked by esophago-salivary reflex, in patients with BE and controls (CTRL).
  
  
  METHODS
  Salivary secretion was collected during basal condition, mastication, and intraesophageal mechanical and chemical stimulations respectively, mimicking the natural gastroesophageal reflux scenario.
  
  
  RESULTS
  Salivary pH in BE was significantly lower than in controls during mechanical (p<0.001) and chemical stimulations (p<0.001). Bicarbonate and protein outputs in BE were significantly lower during mechanical (p<0.05) and chemical stimulations (p<0.01). The non-bicarbonate and glycoconjugate outputs in BE were lower during chemical stimulation (p<0.05) and during mechanical (p<0.05) and chemical stimulations (p<0.05) respectively. The rate of salivary EGF output in BE was significantly lower during mechanical stimulation (p<0.05). We observed a higher TGFα output during mastication (p<0.05) and PGE2 secretion during basal and masticatory condition (p<0.05) in BE.
  
  
  CONCLUSIONS
  Patients with BE demonstrated significantly compromised salivary pH and rate of secretion of bicarbonate, non-bicarbonate, glycoconjugate, protein and EGF. This impairment could potentially predispose to the development of accelerated esophageal mucosal injury. Potential restoration of this impairment by masticatory stimulation of salivary secretion using sugarless chewing gum justifies further clinical exploration.
authors.affiliation: Molecular Medicine Research Laboratory, Department of Internal Medicine, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, TX, USA.
authors.forename: Harathi
authors.initials: H
authors.lastname: Yandrapu
authors.affiliation: Department of Medicine, Columbia County Health System, Dayton, WA, USA.
authors.forename: Marek
authors.initials: M
authors.lastname: Marcinkiewicz
authors.affiliation: Department of Endoscopy, University Hospital 1, Collegium Medicum Bydgoszcz, Nicolaus Copernicus University Torun, Bydgoszcz, Poland.
authors.forename: Cezary
authors.initials: C
authors.lastname: Poplawski
authors.affiliation: Department of Physiology, Medical University of Bialystok, Bialystok, Poland.
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Namiot
authors.affiliation: Department of Reproduction and Gynecological Endocrinology, University Clinical Hospital, Bialystok, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Zbroch
authors.affiliation: Molecular Medicine Research Laboratory, Department of Internal Medicine, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, TX, USA. Electronic address: jerzy.sarosiek@ttuhsc.edu.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Sarosiek
mesh_terms: D000328:Adult; D000368:Aged; D001471:Barrett Esophagus / Q000503:physiopathology*; D015536:Down-Regulation; D004947:Esophagus / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D012021:Reflex, Abnormal; D012463:Saliva / Q000737:chemistry / Q000378:metabolism; D012469:Salivary Glands / Q000378:metabolism / Q000503:physiopathology*; D012472:Salivation
keywords: Barrett's esophagus; Bicarbonate; EGF; Glycoconjugate; Salivary pH