title: Smokeless tobacco-induced lamellar body abnormalities.
abstract: OBJECTIVE
  To compare the morphological changes and quantitative distribution of lamellar bodies (Lb) (membrane coating granules) in the hamster cheek pouch epithelium with smokeless tobacco (ST).
  
  
  METHODS
  Archives of experimental material from previously published studies [S. Ashrafi, A. Das, R. Worawongvasu, B. Mehdinejad and J. Waterhouse (1992) Scanning Microscopy6: 183] were utilized. Animals in experimental group received most ST (snuff) in their right pouch, 5 days weekly, for 24 months, while no snuff was given to control group. After 24 months, the epithelial tissues were processed for electron microscopic study. Volume densities of Lb were assessed by morphometry.
  
  
  METHODS
  Densities of Lb in the two groups, experimental vs control.
  
  
  RESULTS
  In the control, Lb extruded their contents into the intercellular spaces of upper granular layers and in between the last granular cell layers and keratin layers to form a permeability barrier. Conversely, in the smokeless tobacco-treated epithelium, the majority of the Lb that were formed remained inside and accumulated within the granular cells, without extruding their contents into the intercellular spaces to form a lipid compound permeability barrier.
  
  
  CONCLUSIONS
  Commercial alkaline ST may have contributed to the abnormal accumulation of Lb in the granular cell layer and affected the extrusion process of Lb to form an incomplete permeability barrier in the oral epithelium.
authors.affiliation: Department of Oral Medicine and Diagnostic Sciences, College of Dentistry, University of Illinois at Chicago, Chicago, IL 60612-7227, USA. colvard@uic.edu
authors.forename: M D
authors.initials: MD
authors.lastname: Colvard
authors.forename: S H
authors.initials: SH
authors.lastname: Ashrafi
authors.forename: O K
authors.initials: OK
authors.lastname: Alonge
authors.forename: G A
authors.initials: GA
authors.lastname: Cordell
mesh_terms: D000818:Animals; D021961:Cell Membrane Structures / Q000187:drug effects* / Q000648:ultrastructure; D006224:Cricetinae; D004848:Epithelium / Q000187:drug effects* / Q000648:ultrastructure; D005089:Exocytosis / Q000187:drug effects*; D007642:Keratosis / Q000209:etiology; D008297:Male; D008647:Mesocricetus; D046529:Microscopy, Electron, Transmission; D022142:Secretory Vesicles / Q000187:drug effects* / Q000648:ultrastructure; D014030:Tobacco, Smokeless / Q000633:toxicity*