Persistent stunting following x‐irradiation of the fetus

Abstract

CF1 female mice were time mated and the embryos at each gestation day from 0.0 to 18.0 were x-rayed to l O O r and the young carried to four months at which time a skeletal study was made. With this exposure the litters were reduced in size, following irradiation at certain gestation ages, and there was neo-natal mor. tality so that this skeletal study is based upon the survivors to four months and represents the maximum development under the conditions of irradiation. The sex ratio was not altered by this irradiation. Male mice of this strain are always heavier than the females of the same age, and this exposure reduced the over-all average of either sex by 2.5 grams. The skeletal measurements were taken from 1,005 radiographs of the living animals, and the averages calculated for each gestation day. There were sex differences in stunting, even when x-irradiation occurred before day 9.0. When the differences were pronounced the female was the more adversely affected. The highest statistical significance in skeletal effects of seven measurements was between 11 and 13 days, when the embryo shows the earliest skeletal differentia. tion. Such mice were topographically well developed.

Effects of 0.6-Gy Prenatal X Irradiation on Postnatal Neurophysiologic Development in the Wistar Rat

“…Animals irradiated on the 9th day exhibited reduced term fetal weights, which is in agreement with the work of Rugh et al (50)(51)(52) who observed growth retardation in mice following prenatal X irradiation at 1.0 Gy. Jensh et al (53) have shown that there is an inverse relationship between litter size and fetal weight at the extremes of the litter size range, but a significant difference in term fetal weight was also observed following analysis of the data after exclusion of one unusually large (statistical outlier) litter.…”

Recovery From X-Ray Irradiation Injury During Delayed Implantation in the Rat

“…Irradiation of pregnant animals of several species has been shown to cause a depression in foetal weight at term (Wilson et al 1953;Russell & Russell, 19546;Parish, Murphree & Hupp, 1962;Chang et al 1963;Inman & Markivee, 1963;Skreb, Bijelic & Lukovic, 1963;Rugh, Duhamel, Osborne & Varma, 1964). Foetal weight reduction is marked, especially if exposure to irradiation is during the postimplantation period of major organogénesis.…”

2-Mercaptopropionylglycine Protection against Growth-Inhibiting Effects in in utero Irradiated Mice

“…In the former case, the effect may come by reducing the number of certain vital cells by death or by reduction of weight in certain organs. Evidences are that loss of body weight during the post-natal development was due to skeletal malforma tion that resulted from the in utero irradia tion [Levy et al, 1953;Russell, 1956;Rugh et al, 1964]. The initial phase of weight loss of early intervals, therefore, may be due to the direct effect of irradiation.…”