Radioadaptive response for protection against radiation-induced teratogenesis.
To clarify the characteristics of the radioadaptive response in mice, we compared the incidence of radiation-induced malformations in ICR mice. Pregnant ICR mice were exposed to a priming dose of 2 cGy (667 muGy/min) on day 9.5 of gestation and to a challenging dose of 2 Gy (1.04 Gy/min) 4 h later and were killed on day 18.5 of gestation. The incidence of malformations and prenatal death and fetal body weights were studied. The incidence of external malformations was significantly lower (by approximately 10%) in the primed (2 cGy + 2 Gy) mice compared to the unprimed (2 Gy alone) mice. However, there were no differences in the incidence of prenatal death or the skeletal malformations or the body weights between primed and unprimed mice. These results suggest that primary conditioning with low doses of radiation suppresses radiation-induced teratogenesis.
Okazaki
Ryuji
R
Department of Radiation Biology and Health, School of Medicine, University of Occupational and Environmental Health, Japan, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan.
Ootsuyama
Akira
A
Norimura
Toshiyuki
T
D000016:Abnormalities, Radiation-Induced; D000818:Animals; D001835:Body Weight; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005333:Fetus / Q000528:radiation effects*; D017880:Limb Deformities, Congenital / Q000209:etiology; D051379:Mice; D008813:Mice, Inbred ICR; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000528:radiation effects; D011827:Radiation; D011836:Radiation Tolerance