[Determination of parameters of the survival curve of the stem cells of the intestinal crypts by LD50 and the regenerated crypt count. Determination of the RBE of p(65) + Be neutrons].
The early effects of an irradiation on the intestinal epithelium have been evaluated, at the tissular level, by LD50 after single and multifraction irradiation, and, at the cellular level, by numeration of the regenerated intestinal crypts (Withers technique) after a single fraction irradiation. From the set of informations provided by both criteria, one derived the values of the parameters defining the survival curve of the intestinal clonogenic crypt cells after irradiation by gamma-rays (two component model): D0 = 1.5 Gy, 1D0 = 4.5 Gy, nD0 = 2.25 Gy and n = 20. In other respects, the p(65) + Be neutrons RBE (ref. 60-Cobalt) after a single fraction irradiation is equal to 1.75 +/- 0.2 and 1.64 +/- 0.25 for the LD50 at the 5th day and for the regeneration of 50 crypts after 3.5 days respectively.
D000818:Animals; D002452:Cell Count; D005214:Fast Neutrons; D005260:Female; D007413:Intestinal Mucosa / Q000528:radiation effects*; D007928:Lethal Dose 50; D051379:Mice; D009502:Neutrons; D011829:Radiation Dosage; D012062:Relative Biological Effectiveness; D013234:Stem Cells / Q000528:radiation effects*
Détermination des paramètres de la courbe de survie des cellules souches des cryptes intestinales, á partir de la DL50 et de la numération des cryptes régénérées. Détermination de l'EBR des neutrons p(65) + Be.