title: Adaptive response in embryogenesis: I. Dose and timing of radiation for reduction of prenatal death and congenital malformation during the late period of organogenesis.
abstract: An adaptive response was demonstrated during embryogenesis in mice. Whole-body irradiation at a dose of 0-50 cGy was given to condition pregnant ICR mice on day 9 to day 11 of gestation. Then their whole bodies were exposed to a challenging dose of 5 Gy on the next day. The numbers of living fetuses, prenatal deaths and living fetuses with external gross malformations were determined on day 19. A conditioning dose of 30 cGy on day 11 significantly increased the rate of living fetuses and reduced the incidence of congenital malformations induced by a 5-Gy dose on day 12. This indicates the existence of a critical dose and timing for administering a conditioning dose for radioadaptation during the late period of organogenesis in mice. The possible mechanisms involved are discussed.
authors.affiliation: Division of Radiobiology and Biodosimetry, National Institute of Radiological Sciences, Chiba, Japan.
authors.forename: B
authors.initials: B
authors.lastname: Wang
authors.forename: H
authors.initials: H
authors.lastname: Ohyama
authors.forename: T
authors.initials: T
authors.lastname: Nose
authors.forename: H
authors.initials: H
authors.lastname: Itsukaichi
authors.forename: T
authors.initials: T
authors.lastname: Nakajima
authors.forename: O
authors.initials: O
authors.lastname: Yukawa
authors.forename: T
authors.initials: T
authors.lastname: Odaka
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
authors.forename: E
authors.initials: E
authors.lastname: Kojima
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.forename: I
authors.initials: I
authors.lastname: Hayata
mesh_terms: D000016:Abnormalities, Radiation-Induced; D000220:Adaptation, Biological / Q000528:radiation effects*; D000818:Animals; D004307:Dose-Response Relationship, Radiation; D005314:Embryonic and Fetal Development / Q000528:radiation effects*; D005260:Female; D005313:Fetal Death / Q000209:etiology*; D018878:Limb Buds / Q000528:radiation effects; D017880:Limb Deformities, Congenital / Q000209:etiology; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D011247:Pregnancy; D013623:Tail / Q000002:abnormalities; D013997:Time Factors; D014916:Whole-Body Irradiation