Influence of Dietary Potassium,Rubidium,or Sodium on the Retention Time of Radiocesium in Rats ∗

Summary

Increasing the K intake of rats above requirements reduced the half-retention time for ¹³⁴Cs but at a decreasing rate. Maximum intake was 5% which resulted in T_1/2 of 6 days. The Na added at 0.3 or 2% to high K diet had no influence on the T _1/2 for ¹³⁴Cs. The influence of Rb salts on ¹³⁴Cs retention would indicate that this ion is less effective than K. The decreased effect of Rb may be due to its failure to adequately substitute for K in normal muscle cell metabolism.