Transfer of antimony and arsenic to the developing organism.

The transfer of 73As and 125SB to the developing mouse organism was studied in the following ways. a)A diet containing the isotopes was given from the day of the vaginal plug and the radioactivity in uterus, ovaries and different maternal organs was determined 2,4, and 6 days after initiation of feeding. b)The isotopes were injected i.p. during organogenesis at day 12, and the transfer into the fetus as well as activity in maternal organs were followed for a period of 7 days. c)The radioactive diet was supplied during the entire pregnancy and 15 days thereafter. The radioactivity in the females was followed for 150 days, that in the litter for 50 days. Components of turnover of less than a day, less than a week and several months can be discerned in the adult for both isotopes and transfer to the fetus occurs during organogenesis. Less antimony than arsenic is transferred from food during fetal life. After birth, arsenic as well as antimony are taken up by the newborn via the milk.