Urinary excretion of radium in dogs

¹ Department of Radiation Biology, University of Rochester, Rochester, New York

Three female adult dogs were injected intravenously with single doses of radium-226 chloride ranging from 20 to 40 µc. Periodic sampling of blood with added heparin and of urine using a bladder catheter were performed for total elapsed times of from 1 week to 21 weeks. Analyses were made of radium in the plasma, the plasma ultrafiltrate and in the urine. Creatinine was determined in plasma and urine. Radium clearance (average = 1.6 ml/min.), creatinine clearance (average = 46 ml/min.), percentage of the plasma radium which is ultrafilterable (average = 70%), and percentage of the ultra-filtrate which is resorbed (average = 95.3%) have been calculated on a basis of the data obtained. Comparing these values for radium with other comparable published values for strontium and calcium it is inferred that the differences in urinary excretion of these materials is principally caused by differences in resorption in the kidney tubules.