The distribution of 109Cd2+ in the chicken embryo after injection into the yolk prior to incubation

After injecting 109Cd2+ into the vitellus prior to incubation, hen eggs were incubated for up to 17 days. The distribution of the 109Cd2+ in whole eggs or in excised embryos was studied by autoradiography or by gamma spectrometry. The assimilation process of cadmium in the developing embryos started in the early embryogenesis by an accumulation in the embryonic gut. The results indicated a passage of 109Cd2+ from the yolk into the embryo via the vitelline duct at early embryogenesis. There was no increase in the total amount of 109Cd2+ in the embryos from the 4th to the 10th day of incubation although during this period the amount of 109Cd2+ in the chorio-allantoid increased considerably. Concomitantly the amount of 109Cd2+ in the yolk decreased to a similar extent. At a later stage, a high amount of 109Cd2+ was taken up by the embryos via the vitelline circulatory system and 109Cd2+ in the 17 days' embryos was found in specific places in certain tissues. (Author)