Detection of structural changes and developmental disturbances of embryos and fetuses following prenatal X-ray irradiation by means of the osmote active density gradient

Pregnant mice (NMRI) were exposed to whole-body irradiation with 150 kV X-rays on the 12th and 13th day p.c.. 24h p.r. the dissected fetuses were put into a linear gradient solution (NaCl 1-7% or NaCl-Saccharose 1% resp. 5-9%) until sedimentation by active osmosis. The ionising irradiation causes in our experiment model - apart from other effects - a change in the growth rate (retardation) which has to be considered. Dose/effect curves can be set up for a certain age from the corresponding ordinate values. It is worth noticing that a dose of 0,5 Gy (24 h p.r.) already leads to a 20% reduction of the sinking rate compared to the control group. The molecular mechanisms of this irradiaiton effect are not yet clarified; it is, however, highly probable that they are latent disturbancies in the water house hold which are still within the stability range; the lipds have an inhibiting effect on the osmotic water extraction possibly caused by changes in permeability. (orig./MG)