Abstract
To carry out the comparative study on metabolism of 86Rb and 137Cs, whole body retention and tissue distribution after single oral administration to rat were investigated by means of a double tracer method. The result showed marked differences of metabolic behaviour between these two radionuclides. Whole body retention of 86Rb can be expressed by a single component exponential function of time, while that of 137Cs by two components. The time required for attaining the equilibrium distribution pattern is 3 days after administration for 86Rb, while 6 days for 137Cs. At the equilibrium in distribution, 137Cs was concentrated specifically in muscle tissue, while 86Rb concentration in liver and spleen was much higher than 137Cs in these tissues. The present distribution study gave a reasonable interpretation for the results of our previous profile-scanning study on a human subject.
