Dose absorbed by mouse red bone marrow after oral administration of tritiated water

Tritiated water (HTO) was given to mice orally. Dose accumulation patterns in various organs and tissues after oral HTO intake were compared with those after intraperitoneal injection. The accumulated dose was 10-20% higher after intraperitoneal injection than after oral administration. A new technique was developed to isolate mouse red bone marrow from tibia. The absorbed beta-ray dose in the red bone marrow after oral tritium intake was lower than the body-averaged dose that was estimated based on the tritium concentration in the urine or the blood and higher than the absorbed dose in the liver and testis.