ABSORPTION AND FETAL METABOLISM OF CESIUM 137 IN THE RAT

Journal Article · Thu Feb 01 04:00:00 EST 1962 · Dissertation Abstr.

OSTI ID:4838140

Moore, W Jr

Detailed studies in the rat were done on the following aspects of radiocesium metabolismn rates and mechanisms of gastrointestinal absorption, interrelationships with potassium, and magnitude and rates of placental transfer. Cs/sup 137/ was absorbed rapidly and completely, after oral administration, from the gastrointestinal tract of the rat. Absorption occurred from all anatomical areas studied, with the small intestine being the most important site of absorption. The stomach and cecum absorbed only minute quantities. Using Dowex 50 resin as a trapping agent, total endogenous secretion was measured over the first hour after injection. Total endogenous secretion amounted to approximately 25% of the initial dose for the time period studied. Total absorption of Cs/sup 131/ from the gastrointestinal tract amounted to 98% of the initial dose for the first hour after administration as estimated by taking endogenous secretion into consideration. The data indicated a gradient of absorptive efficiency with the duodenum having the highest rate of absorption and endogenous secretion and the colon the smallest. Increased concentrations of stable potassium or cesium in the dosing solutions studied, did not significantly affect absorption. However, gastric emptying time was increased with each increase in concentration of potassium or cesium. Cs/sup 137/ was not transferred from the mucosal side to the serosal side of surviving intestinal segments against a concentration gradient using in vitro procedures. However, a net transfer did occur from the serosa to the mucosa, suggesting the presence of a mechanism for the transfer of Cs/sup 137/ in this direction. Cs/sup 137/ appeared rapidly in the fetus after oral administration to the dam. The fetal uptake was rapid for the first several hours and then decreased reaching a steady-state with maternal blood in approximately 16 hours. The general pattern of distribution was the same in the fetuses as in the dam, however, the accumulating ability of fetal tissues was less. The Cs/sup 137/K ratio was greater in the dam than in the fetus. The percentsge dose per gram of fetal tissue appeared to be independent of age or weight of the fetus. Cs/sup 137/ migrated readily across the placental membrane. About 85% of that administered migrated to the dam after fetal injection, and about 25% migrated from the dam to fetus after maternal injection. The data provide a basis for understanding sorae aspects of the movement and metabolism of cesium in animals and man and the factors that govern its behavior.

• Research Organization: Cornell Univ., Ithaca, N.Y.
• NSA Number: NSA-16-021884
• OSTI ID: 4838140
• Journal Information: Dissertation Abstr., Journal Name: Dissertation Abstr. Vol. Vol: 22
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ABSORPTION
AGE
BIOLOGY AND MEDICINE
BLOOD
CESIUM
CESIUM 137
FETUSES
INTESTINE
METABOLISM
POTASSIUM
QUANTITY RATIO
RATS
SOLUTIONS
STOMACH
TISSUES
TRACER TECHNIQUES
WEIGHT