[Radiobiological aspects of increased radioresistance of murine epithelial stem cells from patches of Peyer].

The fraction of the survived intestinal crypts associated with patches of Peyer is higher to those non-patch-associated crypts of mice for three inbred strains. The difference in the survival between associated and non-patch-associated crypts increases with dose of gamma-irradiation. This difference for old mice is less than for young mice. Pre-irradiation (5 Gy) of mice one week before the conditioned gamma-irradiation cannot modify the difference in the survival between associated and non-patch-associated crypts. Radioprotection of mice by hypoxic gas mixture (10% O2) cannot modify this difference. Pre-treatment of mice by dextran-sulfate alone or in combination with hypoxic gas mixture decreased the survival of intestinal crypts associated with patches of Peyer to the level of non-path-associated crypts. The difference in the survival between two subpopulation of intestinal stem cells is less after neutron irradiation than after gamma-irradiation.