Analysis of hematopoiesis in mice irradiated with 500 mGy of X rays at different stages of development.
We have investigated whether a relatively low dose of 500 mGy of X rays given as a single acute irradiation at different stages of pre- and postnatal development induces significant changes in the content of femoral hematopoietic progenitors during a 1-year period after irradiation. Data obtained show that, in the case of 4-day-old embryos as well as in 2-day, 8-day and 12-week-old mice, this dose is below the threshold capable of inducing a long-term impairment of hematopoiesis in the mouse. Nevertheless, in mice irradiated at the 13th or the 17th day postconception, a hematopoietic dysfunction consisting of a significant reduction in the proportion of femoral granulocyte-macrophage colony-forming units (CFU-GM) was manifested 1 year after irradiation. Our study confirms that, for most stages of development in the mouse, a single acute X irradiation of 500 mGy is below the threshold dose capable of inducing deterministic effects in the mouse hematopoietic system, although it reveals the induction of a significant impairment in the CFU-GM population when irradiation is given at the late stages of embryonic development.
Grande
T
T
U. de Biología Molecular y Celular, CIEMAT, Madrid, Spain.
Bueren
J A
JA
D000367:Age Factors; D000818:Animals; D005260:Female; D006410:Hematopoiesis / Q000528:radiation effects*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D011829:Radiation Dosage; D014965:X-Rays