Epidermal morphology, cell proliferation and repopulation in mouse skin during daily fractionated irradiation.
In mouse, a 2 cm long field of both legs was irradiated daily with 3 Gy, five fractions per week for up to 3 weeks. Epidermal morphology, the circadian variation of the labelling index, and repopulation were determined at the end of each week. After a decrease of epidermal cellularity in the first week, excessive regeneration led to hyperplasia and hypertrophy, which continued throughout the experimental period while the residual tolerance of the epidermis to top-up irradiation decreased progressively. Although the repopulation rate was accelerated five-fold, it was unable to compensate the effects of more than two-thirds of the given dose. The hypertrophic and hyperplastic response is attributed to pronounced acceleration of abortive proliferation of doomed stem cells.
Shirazi
A
A
Department of Radiation Biology, St Bartholomew's Medical College, London, UK.
Liu
K
K
Trott
K R
KR
D000818:Animals; D002455:Cell Division / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D000078404:Epidermal Cells; D005260:Female; D051379:Mice; D008815:Mice, Inbred Strains; D012867:Skin / Q000166:cytology / Q000528:radiation effects*; D014965:X-Rays