Reliability of inulin for determining volume flow in rat renal cortical tubules

Abstract

The recovery of inulin was complete when perfused by micropuncture into single proximal tubules and collected from the corresponding distal tubule. Systemic infusion of inulin during similar experiments revealed no inulin secretion. Inulin-C¹⁴ was completely recovered in the urine when injected into single proximal tubules. These experiments provide direct affirmation of the assumption that inulin is conserved in the tubule lumen.