EXPERIENCES WITH RADIOSULFATE IN THE ESTIMATION OF PHYSIOLOGIC EXTRACELLULAR WATER IN HEALTHY AND ABNORMAL MAN 12

Abstract
S35 tagged sodium sulfate was given by single intravenous injection to 37 subjects. Concentrations of S35 were measured in plasma and urine and the disappearance rates calculated. Calculations for "zero time" volume of distribution corrected for equilibrium time urinary excretion are made. Mean values, as per cent of body weight, in healthy subjects were 19.1 for young soldiers, 16.7 for sedentary young men, 14.9 for elderly men and 15.5 for elderly women. The sodium radiosulfate space was reproducible, and corresponds well with simultaneously determined inulin spaces. A period of 3.4 to 5.1 hours was required for equilibration with ascitic fluid. A method of calculating the slowly exchanging sulfate pool was described.