摘要：Radio-adaptive responses at a conditioning X-ray dose of 0.45 Gy and a challenging dose of 5.0 Gy on hematopoietic indices were studied in C57BL mice with p53 ( Trp53 ) wild, heterogenous and knockout allele. The conditioning irradiation, given 2 weeks before the challenging irradiation, induced radio-adaptive responses observed as a recovery of the peripheral blood-cell counts of leukocytes, thrombocytes and erythrocytes on day 14 after challenging irradiation in C57BL mice of the wild-type p53 ( / ). The pre-irradiation also increased the endogenous spleen colonies (endo-CFU-S) on day 12 and the spleen weight on day 14. On the contrary, the knockout p53 ( -/-) mice gave no such radio-adaptive response. The heterogenous p53 ( /- ) mice gave an intermediate response. The radio-adaptive response in hematopoiesis at a challenge dose of 5.0 Gy seems to be a p53 -dependent phenomenon. The possible role of induction in radio-resistance through the reduction of p53 -drived apoptosis in hematopoietic stem cells in pre-irradiated mice is discussed.
