title: Accelerated repopulation of mouse tongue epithelium during fractionated irradiations or following single doses.
abstract: Mouse tongue mucosa was established as an animal model to study repopulation after large single doses or during continuous irradiation. A top-up irradiation technique was used employing priming doses or fractionated treatment to the whole snout (300 kV X-rays) followed by local test doses (25 kV X-rays) to elicit denudation in a confined field of the inferior tongue surface. Clearcut quantal dose-response curves of ulcer incidence were obtained to all protocols; animal morbidity, i.e. body weight loss was minimal. Repopulation following priming doses of 10 and 13 Gy started with a delay of at least 3 days and then progressed rapidly to nearly restore original tissue tolerance by day 11. During continuous fractionation over 1 to 3 weeks with 5 fractions/week and doses per fraction of 2.5, 3 and 3.5 Gy, repopulation was small in week one but subsequently increased to fully compensate the weekly dose at all dose levels. Additional measurements of cell density during a 4 weeks course of 5 x 3 Gy or 5 x 4 Gy per week showed only moderate depletion to 67% of the control figures. The fact that rapid repopulation is achieved at relatively moderate damage levels should be taken into account when the timing of a treatment split is considered.
authors.affiliation: GSF, Institut für Strahlenbiologie, Neuherberg, F.R.G.
authors.forename: W
authors.initials: W
authors.lastname: Dörr
authors.forename: J
authors.initials: J
authors.lastname: Kummermehr
mesh_terms: D000818:Animals; D004307:Dose-Response Relationship, Radiation; D004848:Epithelium / Q000473:pathology / Q000528:radiation effects; D005260:Female; D051379:Mice; D008809:Mice, Inbred C3H; D008954:Models, Biological; D009061:Mouth Mucosa / Q000473:pathology / Q000528:radiation effects; D011833:Radiation Injuries, Experimental / Q000473:pathology; D011836:Radiation Tolerance; D013280:Stomatitis / Q000473:pathology; D013997:Time Factors; D014059:Tongue / Q000528:radiation effects*