Use of Thiosulfate Clearance As a Measure of Glomerular Filtration Rate in Acidotic Dogs. ∗

Summary and Conclusions

The data presented above confirm the observations of Gilman et al. ¹ that the thiosulfate clearance may be used as a valid measure of glomerular filtration rate in the dog, and extend these observations by showing that it is applicable to animals with disturbed acid base relationships as well as to normal animals. Because the administration of thiosulfate has no significant effect on glomerular filtration rate (creatinine clearance) and minimum effective renal plasma flow (p-aminohippurate clearance) the thiosulfate clearance may be used in studies on renal function in acidotic animals with minimal disturbance of these discrete renal variables. Since thiosulfate is not a buffer, the administration of this substance does not greatly alter the rate of excretion of titratable acid. This virtue is likewise possessed by mannitol and inulin, but the simplicity and accuracy of the thiosulfate analysis argues strongly in its favor.