Distribution of Cesium in the Organism and Its Effect on the Nucleotide Metabolism Enzymes

Abstract

After the intraperitoneal administration of 0.5 mEq 134CsCl • kg^-1 to mice, the maximum cesium level in the kidneys, heart, lungs and liver was found in the first hour (T(1/2) 13 h), in the muscles after 8 h (T(1/2) 180 h), in the brain after 24 h (T(1/2) 140 h) and in the blood after 24 h. Maximum cesium levels were found in the muscles. Rats excreted about 17% of the administered dose in 24 h and 38% in 144 h. Most of the cesium (about 90%) is excreted in the urine. In rats, equalization of the plasma and RBC cesium levels takes longer than 6 h. Cesium transport is not entirely dependent on the ATPase system, as shown by the results given by the crude mitochondrial fraction with a reduced potassium content. Among the various univalent ions studied, the effect of cesium on creatine kinase, 5'-nucleotidase, phosphodiesterase and deaminase activity was the smallest.