Rate of excretion of radioactive sulfur and its concentration in some tissues of the rat after intraperitoneal administration of labeled sodium sulfate.

A study of the distribution of S35 in the rat, 14 to 16 hours after the intraperitoneal administration of sodium sulfate, labeled with S35, has been reported by Singher and Marinelli (1). Of particular interest is their observation that the highest concentration of the radioactive sulfur was found in the bone marrow. This observation stimulated us to determine the change with time in the concentration of $Y5, given as labeled sodium sulfate, in the bone marrow of the rat and to relate this changing concentration with the concentration in other tissues, particularly the blood. Only a brief report (2) was found in the literature on the excretion in urine of Ss5 ingested as sodium sulfate. The rate of excretion of S35 in the urine and feces of rats after intraperitoneal injection of labeled sodium sulfate was, therefore, also determined.