Micropuncture Study of Inulin Absorption in the Rat Kidney

Abstract

By means of a microinjection technique, inulin-carboxyl-C(14) or inulin-methoxy-H(3) was injected into single proximal tubules of the rat at various urine flow rates. Urine collected separately from the two kidneys showed negligible amounts of inulin activity on the noninjected side, thus demonstrating directly that there is no significant reabsorption of inulin by the renal tubular epithelium under these conditions.