Changes in the width of epithelial cells in the healing excised cutaneous wound.

An account is given of the changes which take place in the width of epithelial cells over and around healing full-thickness excised skin wounds in the thoracic and metatarsal regions of the dog. Cellular hypertrophy extended for a distance of 4 mm into the surrounding epidermis. The widest basal cells occurred at the wound edge and close to the tip of the migrating epithelial sheet; thus they were found in regions where the rate of mitotic division was greatest. The width of the hypertrophic basal cells was 210 to 240 per cent greater than that of the normal basal cell. The maximum width of the spinosal cells was 17-9 mum which was 15 to 20 per cent wider than the underlying basal cells. The relatively large area covered by the enlarged migrating spinosal cells increased the rate at which the wound surface was covered with epithelium.