title: Effect of in utero radiation dose fractionation on rat postnatal development, behavior and brain structure: 3-hour interval.
abstract: Effect of In Utero Radiation Dose Fractionation on Rat Postnatal Development, Behavior and Brain Structure: 3-Hour Interval. Neurotoxicology 15(1): 183-190, 1994. We have previously shown that exposure of the rat fetus to ionizing radiation produces dose-dependent (0.25-1.25 Gy) changes in postnatal growth and behavior, and decreases in cerebral cortex thickness. Pregnant rats were exposed to single doses of 0.5 or 1.0 Gy, or to two doses of 0.5 Gy (separated by a 3 h interval) on gestational day 15. Pups were weighed and subjected to behavioral tests (righting reflex; reflex suspension; negative geotaxis; continuous corridor; and length, width, and sine of gait) over postnatal days 7-28. The rats were then sacrificed and brains removed for histology. The fractionated doses produced responses that were generally intermediate between those produced by the single doses and which, by interpolation, could be expressed as equivalent to a single dose between 0.5 and 1.0 Gy. Overall, exposure of the fetal rat to two doses of 0.5 Gy separated by 3 h produced effects equivalent to a single dose of 0.85 Gy. We conclude that fractionation of radiation dose results in less damage to the developing rat cerebral cortex, as measured by postnatal growth, behavioral tests, and morphological assessment.
authors.affiliation: Department of Radiation Oncology, University of Kansas Medical Center, Kansas City 66160-7321.
authors.forename: B F
authors.initials: BF
authors.lastname: Kimler
authors.forename: G M
authors.initials: GM
authors.lastname: Vidal-Pergola
authors.forename: S L
authors.initials: SL
authors.lastname: Peterson
authors.forename: X
authors.initials: X
authors.lastname: Li
authors.forename: S
authors.initials: S
authors.lastname: Norton
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000528:radiation effects*; D001835:Body Weight / Q000528:radiation effects; D001921:Brain / Q000254:growth & development* / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005684:Gait / Q000528:radiation effects; D005865:Gestational Age; D006128:Growth / Q000528:radiation effects*; D008098:Litter Size / Q000528:radiation effects; D008297:Male; D004856:Postural Balance / Q000528:radiation effects; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D017207:Rats, Sprague-Dawley