Absorption of D-[{sup 14}C]-glucose and D-[{sup 3}H]-mannose in everted rat jejunum

Radiolabeled elements are useful in measuring physiologic processes in mammalian tissues. Absorption of D-[{sup 14}C]-glucose is often used as a marker for active transport by the sodium-dependent transmembrane glucose/galactose carrier, SGLT1, present in epithelial tissues. Also, D-[{sup 3}H]-mannose monitors the flux of a passively absorbed hexose through the intestinal wall. Many gastrointestinal absorption studies have employed the everted gut sac method developed by Wilson and Wiseman in 1954. Phloridzin is a glycoside derived from apple trees and an effective inhibitor of the sodium-dependent glucose carrier. It was hypothesized that a kinetic study of radiolabeled hexoses could be successfully applied to a modification of this method and assayed by an inhibitory effect of phloridzin on D-[{sup 14}C]-glucose influx into everted rat jejunum and that glycosides transported by the sodium-dependent glucose transporter would have a similar inhibitory effect on D-[{sup 14}C]-glucose influx.