Comparison of the Volumes of Distribution of Inulin, Sucrose and Thiosulfate in Normal and Nephrectomized Dogs

Abstract

In 4 normal dogs, the volume the distribution of inulin was 16-19% of body weight. When a single-injn. technic was used in the same animals, the apparent volume of distribution of sucrose, after a slow injn., was 18-21% of body wt., and after a rapid injn., 21-23% of body wt. The apparent volume of distribution of thiosulfate was found to be 20-24% of body wt., after slow injns. and 24-40% after rapid injns. In nephrectomized animals, sucrose and thiosulfate had similar volumes of distribution, while the volume of distribution of inulin was consistently smaller. Sucrose is not rapidly destroyed in nephrectomized dogs and its rate of clearance from plasma after single injn. in normal dogs approximates the G.F.R. Incomplete urinary recovery appears to be attributable to loss in urine and/or tubule cells. The sources of error are discussed. The data suggest that the physiologic volumes of distribution of sucrose and thiosulfate are probably equal, and that the volume of distribution of inulin is smaller than that of the other 2 materials.