The Relative Distributions of Radioactive Yttrium and Strontium and the Secondary Deposition of ⁹⁰Y Built up from ⁹⁰Sr

Summary

Weanling rabbits were injected intravenously with one of three solutions: (1) ⁹⁰Sr (free from ⁹⁰Y), (2) ⁹⁰Sr + ⁹⁰Y in equilibrium, and (3) ⁹¹Y, to compare the relative distributions of strontium and yttrium and to establish whether ⁹⁰Y formed by ⁹⁰Sr decay escaped from sites of its original deposition. The animals were sacrificed at different times up to 30 days after injection, and samples of bone and soft tissues were assayed by means of a beta scintillation counter. The measurements on bone showed the concentrations (in µc/g of bone) of strontium and yttrium to be approximately equal. Soft tissues showed a much higher concentration of yttrium than of strontium, but those having highest concentrations of yttrium also had relatively high concentrations of strontium, namely cartilage, pituitary and kidney.

Measurements of the ⁹⁰Y built up when ⁹⁰Sr (free from ⁹⁰Y) was injected showed that ⁹⁰Y was built up in the liver in excess of the amount predicted from the deposition of ⁹⁰Sr.