Measurement of Extracellular Fluid Volume in Nephrectomized Dogs1

Abstract

Volumes of distribution of radiosulfate, thiosulfate, mannitol, sucrose, raffinose and inulin were compared simultaneously in nephrectomized dogs. Radiosulfate, thiosulfate and mannitol distribute in equal volumes. These volumes average 22.6% of body weight and contain on an average 83% of the total body chloride. The average ratio of sucrose volume to mannitol volume is 0.91; of raffinose volume to mannitol volume, 0.87; and of inulin volume to mannitol volume, 0.74. Intravenous insulin, shown by others to increase volumes of distribution of several slowly metabolized carbohydrates, increases the raffinose volume but does not change volumes of distribution of the other 5 substances.