title: Expression of vanilloid receptor-1 in epithelial cells of human antral gastric mucosa.
abstract: OBJECTIVE
  Capsaicin, which acts by binding to the vanilloid receptor-1 (VR1), has been shown to give protection against gastric mucosal injury and to enhance healing of gastric ulcers. Although VR1 has recently been reported to be present in non-neural tissues, it is primarily considered to be expressed in nociceptor sensory neurons of small diameter. The aim of the present study was to evaluate the distribution of VR1 immunoreactivity in the normal human gastric mucosa.
  
  
  METHODS
  Ten volunteers underwent gastroscopy and biopsies were obtained from the corpus and the antrum. The specimens were labelled immunohistochemically using polyclonal goat anti-VR1 and evaluated at the light- and electronmicroscopic level. Moreover, post-embedding immunogold labelling was performed and subsequently analysed at the electronmicroscopic level.
  
  
  RESULTS
  In the antrum, VR1 immunoreactivity was located in epithelial cells that fulfilled the criteria of endocrine cells of the "open type". These cells were located primarily in the neck region of the antral glands and the labelling was concentrated on the microvilli of these cells. At the ultrastructural level, round granulae with differences in electron density were identified in the basal compartment of the labelled cells. VR1 immunoreactivity was also identified in axon-like structures that were located in the lamina propria, often in close vicinity of vessels, in the corpus as well as in the antrum.
  
  
  CONCLUSIONS
  VR1-immunoreactivity was evident in antral epithelial cells exhibiting characteristics of endocrine-like cells. This may indicate that the gastroprotective effects of capsaicin, which hitherto have been attributed to primary afferent neurons, at least partly may be explained by an action on specific epithelial cells in the antrum.
authors.affiliation: Division of Internal Medicine, Department of Medicine and Care, University Hospital, Linköping, Sweden.
authors.forename: Stergios
authors.initials: S
authors.lastname: Kechagias
authors.forename: Sofia
authors.initials: S
authors.lastname: Botella
authors.forename: Fredrik
authors.initials: F
authors.lastname: Petersson
authors.forename: Kurt
authors.initials: K
authors.lastname: Borch
authors.forename: Ann-Charlott
authors.initials: AC
authors.lastname: Ericson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis; D001707:Biopsy, Needle; D002478:Cells, Cultured; D015331:Cohort Studies; D004847:Epithelial Cells / Q000378:metabolism / Q000502:physiology; D005260:Female; D005753:Gastric Mucosa / Q000166:cytology / Q000378:metabolism* / Q000473:pathology; D005773:Gastroscopy / Q000379:methods; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D011706:Pyloric Antrum / Q000166:cytology / Q000378:metabolism* / Q000473:pathology; D011955:Receptors, Drug / Q000032:analysis*; D012016:Reference Values; D012680:Sensitivity and Specificity; D013276:Stomach Ulcer / Q000503:physiopathology*
chemical_list: D015415:Biomarkers; D011955:Receptors, Drug