In vivo restitution of airway epithelium

Cell Tissue Res. 1995 Aug;281(2):305-16. doi: 10.1007/BF00583399.


Epithelial shedding occurs in health and, extensively, in inflammatory airway diseases. This study describes deepithelialisation, reepithelialisation and associated events in guinea-pig trachea after shedding-like epithelial denudation in vivo. Mechanical deepithelialisation of an 800-microns wide tracheal zone was carried out using an orotracheal steel probe without bleeding or damage to the basement membrane. Reepithelialisation was studied by scanning- and transmission electron microscopy and light microscopy. Nerve fibres were examined by immunostaining. Cell proliferation was analysed by [3H]-thymidine autoradiography. Immediately after epithelial removal secretory and ciliated (and presumably basal) epithelial cells at the wound margin dedifferentiated, flattened and migrated rapidly (2-3 microns/min) over the denuded basement membrane. Within 8-15 h a new, flattened epithelium covered the entire deepithelialised zone. At 30 h a tight epithelial barrier was established and after 5 days the epithelium was fully redifferentiated. After completed migration an increased mitotic activity occurred in the epithelium and in fibroblasts/smooth muscle beneath the restitution zone. Reinnervating intraepithelial calcitonin gene-related peptide-containing nerve fibres appeared within 30 h. We conclude that (1) reproducible shedding-like denudation, without bleeding or damage to the basement membrane, can be produced in vivo; (2) secretory and ciliated cells participate in reepithelialisation by dedifferentiation and migration; (3) the initial migration is very fast in vivo; (4) shedding-like denudation may cause strong secretory and exudative responses as well as proliferation of epithelium, and fibroblasts/smooth muscle. Rapid restitution of airway epithelium may depend on contributions from the microcirculation and innervation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Basement Membrane / cytology
  • Basement Membrane / physiology
  • Cell Differentiation
  • Cell Movement
  • Epithelial Cells
  • Epithelium / physiology
  • Guinea Pigs
  • Male
  • Mitosis / physiology
  • Mucous Membrane / physiology
  • Time Factors
  • Trachea / cytology
  • Trachea / innervation
  • Trachea / physiology*
  • Tracheotomy
  • Wound Healing / physiology