title: The remodelled tracheal basement membrane zone of infant rhesus monkeys after 6 months of recovery.
abstract: BACKGROUND
  In previous studies, we showed that repeated exposure to (1) house dust mite allergen (HDMA) (Dermatophagoides farinae) caused thickening of the basement membrane zone (BMZ) and (2) HDMA+ozone (O3) caused depletion of BMZ perlecan and atypical development of BMZ collagen (irregular thin areas<2.0 microm in width).
  
  
  OBJECTIVE
  The purpose of this study was to determine if these remodelling changes were reversible after 6 months of recovery.
  
  
  METHODS
  Rhesus monkeys were exposed to a regimen of HDMA and or O3 or filtered air (FA) for 6 months. After the exposure protocol was completed FA and O3 groups were allowed to recover in FA for 6 months. The HDMA and HDMA+O3 exposure groups recovered in a modified environment. They were re-exposed to HDMA aerosol for 2 h at monthly intervals during recovery in order to maintain sensitization for pulmonary function testing. To detect structural changes in the BMZ, collagen I and perlecan immunoreactivity were measured and compared to data from the previous papers.
  
  
  RESULTS
  The remodelled HDMA group had a significantly thicker BMZ and after 6 months of recovery the width had not regressed. In the remodelled BMZ of the HDMA+O3 group, perlecan had returned to the BMZ after 6 months of the recovery protocol, and the thin, irregular, collagen BMZ had been resolved.
  
  
  CONCLUSIONS
  In summary, this study has shown that: (1) The width of the remodelled HDMA BMZ did not regress during a recovery protocol that included a sensitizing dose of HDMA. (2) The atypical collagen BMZ in the HDMA+O3 BMZ was resolved in the absence of O3. (3) Depletion of perlecan from the BMZ by O3 was reversed by recovery in the absence of O3.
authors.affiliation: Department of Anatomy, Physiology & Cell Biology; Center for Comparative Respiratory Biology and Medicine, School of Veterinary Medicine, University of California, Davis, CA 95616, USA. mevans@ucdavis.edu
authors.forename: M J
authors.initials: MJ
authors.lastname: Evans
authors.forename: M V
authors.initials: MV
authors.lastname: Fanucchi
authors.forename: G L
authors.initials: GL
authors.lastname: Baker
authors.forename: L S
authors.initials: LS
authors.lastname: Van Winkle
authors.forename: L M
authors.initials: LM
authors.lastname: Pantle
authors.forename: S J
authors.initials: SJ
authors.lastname: Nishio
authors.forename: E S
authors.initials: ES
authors.lastname: Schelegle
authors.forename: L J
authors.initials: LJ
authors.lastname: Gershwin
authors.forename: L A
authors.initials: LA
authors.lastname: Miller
authors.forename: D M
authors.initials: DM
authors.lastname: Hyde
authors.forename: C G
authors.initials: CG
authors.lastname: Plopper
mesh_terms: D000818:Animals; D039741:Antigens, Dermatophagoides / Q000494:pharmacology*; D001485:Basement Membrane / Q000737:chemistry* / Q000276:immunology / Q000473:pathology; D024042:Collagen Type I / Q000032:analysis; D040001:Dermatophagoides farinae; D019812:Heparan Sulfate Proteoglycans / Q000032:analysis; D006967:Hypersensitivity / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D007150:Immunohistochemistry / Q000379:methods; D008253:Macaca mulatta; D008856:Microscopy, Fluorescence; D010126:Ozone / Q000494:pharmacology; D013997:Time Factors; D014132:Trachea / Q000378:metabolism*
chemical_list: D039741:Antigens, Dermatophagoides; D024042:Collagen Type I; D019812:Heparan Sulfate Proteoglycans; C071927:perlecan; D010126:Ozone