Distribution of(31)Silicon-Labeled silicic acid in the rat.

Carrier-free(31)Silicon ((31)Si) prepared by neutron activation, was injected in the form of(31)Si-labeled silicic acid into five albino male rats, and the organ and tissue distribution of labeled silicic acid was determined at sacrifice after 30 min. The kidney was found to contain 0.85% of the injected dose (ID) per gram of tissue; skin had 0.3% ID/G; testes 0.29; bone 0.26; liver 0.22; and brain 0.13. When expressed as % ID/organ, voluntary muscle had 14.6%; skin 10.8; bone 3.4; liver 1.6; kidneys 1.5; testes 0.8, and brain 0.2. These results indicate the need for further research into silicon metabolism in kidney, skin, bone, and brain.