Extracellular space estimation in rat kidney slices using C14 saccharides and phlorizin

Abstract

Estimation of the extracellular fluid space of rat kidney cortex slices with C¹⁴-labeled inulin, sucrose, dulcitol, and mannitol suggest that only inulin is confined to an extracellular location in this tissue. The other saccharide molecules studied penetrate tissue cells in kidney slices to a variable degree, and therefore, are not suitable for the estimation of the extracellular compartment. The present studies also indicate that phlorizin inhibits the cellular penetration of sucrose, dulcitol, and mannitol, and thus may be useful in determining whether a given sugar molecule is or is not limited to an extracellular location.