Acquired Radioresistance: A Review of the Literature and Report of a Confirmatory Experiment

The Adaptive Response and Protection against Heritable Mutations and Fetal Malformation

“…A number of studies have demonstrated adaptive response at the whole-animal level in vertebrates. Some of the documented positive effects of pre-irradiation have included: reduced short-term mortality rates in mice, [1][2][3][4] reduced frequency of chromosome abnormalities in mice 5,6 and humans [7][8][9] , and reduced risk of cancer development in mice. [10][11][12] These studies provide clear evidence for reduction and/or delay of genetic instability and ultimately disease through adaptive response; however, the majority of both in vivo and in vitro studies have focused on somatic markers of DNA damage or cancer.…”

Chronic Whole-Body Gamma Radiation Stress in the Albino Rat and Mouse

“…No mortalities were obtained in a third group which was given only the conditioning dose. Dacquisto (1959) reports an experiment by Bonet-Mvlaury in which 415 r was given over a period of 55 days in multiple small doses (17 to 72 r). A dose of 800 r was given the mice 16 days after the completion of this "conditioning" dose.…”

“…White mice of the Walter Reed strain were shown by Dacquisto (1959) to develop a definite radioresistance. The LD 1 0 ( 3 0 is 487 ± 25.7 r if they receive no radiation, however, if they are given t0 r whole body radiation 10 days prior this figure increases to 560 r ± 31.0 r; and if the period is 17 days the LD30(30) becomes 617 r ± 32.0 r. One explanation suggested for this point to hematopoietic stimulation as a possible mechanism along with others.…”

X-Ray-Induced Radioresistance Against High-LET Radiations from Accelerated Neon-Ion Beams in Mice

“…Since the editio princeps of the AR concept introduced into radiation biology (Olivieri et al, 1984), this phenomenon has been demonstrated both in vitro and in vivo (Takahashi & Ohnishi, 2009;Mitchel, 2006;Vares et al, 2006). Though studies on the radiation-induced radioresistance in rodents in vivo could be retrospected to the later 1940s (Dacquisto, 1959), the first full-dress investigation on AR in mice started about 50 years later by Yonezawa and colleagues (Yonezawa et al, 1990). In a series of comprehensive studies, a variety of experimental condition combinations of the priming and challenging doses, the interval between the irradiations, and the mouse strain were testified and verified (Yonezawa, 2006), laying a cornerstone of in vivo model for AR in mice -successful establishment of the mouse models for AR induction by acute low liner energy transfer (LET) X-irradiations at the whole body level using survival from bone marrow death as the main endpoint, which is the so-called "Yonezawa Effect" in Japan (Takahashi & Ohnishi, 2009).…”