DISTRIBUTION AND MATERNO-FETUS MATERNO-SUCKLING TRANSFER OF TRITIUM AFTER SINGLE INJECTION OF TRITIATED-WATER IN MICE

The metabolism and transfer of tritium from pregnant mice to fetus aft er injection of tritiated water intraperitoneally was investigated in this paper. The study was composed of three experiments. 1. Pregnant m ice were injected with tritium water on the first day of pregnancy, in order to obtain a transfer coefficient of tritium from pregnant mice to fetus through placenta. 2. Pregnant mice were injected with tritiat ed water on the first day of parturition to study the transfer of trit ium via mother milk from nursing mice to the baby-animals. 3. Pregnant mice were injected with tritiated water in different periods of gesta tion. The results showed that tritiated water was uniformly distribute d in all of the tissues measured, including placenta, fetal membrane a nd amniotic fluid in experiment 1. No effect of placentas on tritium t ransfer from pregnant mice to fetus was found. Concentration of tritiu m in the baby's tissues was evidently higher than that in the pregnant mice in experiments 2 and 3, and the transfer coefficient in experime nts 2 and 3 was generally higher than that in experiment 1.