Specific Activity of Inulin-C 14 OOH in Serum and Lymph of Nephrectomized Dog. ∗

Abstract

Summary

Following intravenous injection of inulin-C¹⁴OOH and inulin into a nephrectomized dog, the thoracic duct lymph was considerably higher than serum in specific activity, falling gradually to serum values. The fractionation of the smaller inulin-C¹⁴OOH molecules in lymph formation was thus similar to that observed in ultrafiltration through cellophane membranes, but it was quantitatively of insufficient magnitude to effect an observable decrease in serum inulin specific activity. It is suggested that the decrease in urine specific activity previously reported for the intact dog was due to a quicker uptake of inulin-C¹⁴OOH than non-labelled inulin by renal tissue.