Stimulation of non-sodium-dependent water, electrolyte, and glucose transport in rat small intestine by gum arabic.
In experimental models of gastroenterological disease, the soluble fiber gum arabic (GA) acts as a proabsorptive adjuvant. This study investigated which specific transport pathway(s) are affected by GA. Rat jejunum was perfused under anesthesia with a standardized oral rehydration solution (ORS) containing D-glucose, with or without GA (2.5 g/liter). In some preparations either phloridizin, a competitive inhibitor of Na+-coupled D-glucose transport, or phloretin, an inhibitor of basolateral glucose transport, were added to the ORS, with or without GA. Diffusion and paracellular transport changes due to GA were evaluated with L-glucose and [14C]polyethlyene glycol 4000 (PEG). GA partially reversed water, Na+, and D-glucose absorption inhibition induced by phloridzin and normalized water and Na+ absorption in the presence of phloretin. GA also increased absorption of water, Na+, and PEG from an L-glucose ORS. The data suggest that GA does not act via Na+ dependent mechanism(s), but stimulates transcellular and/or transjunctional transport pathways; therefore GA may be useful to increase absorption of solutes transported by diffusion.
Wingertzahn
M A
MA
Department of Pediatrics, North Shore-Long Island Jewish Health System--New York University School of Medicine, Manhasset 11030, USA.
Teichberg
S
S
Wapnir
R A
RA
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D004058:Diffusion; D004573:Electrolytes / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D006170:Gum Arabic / Q000494:pharmacology*; D007408:Intestinal Absorption / Q000187:drug effects; D007421:Intestine, Small / Q000378:metabolism*; D007583:Jejunum / Q000254:growth & development / Q000378:metabolism; D008297:Male; D010695:Phlorhizin / Q000494:pharmacology; D051381:Rats; D014867:Water / Q000378:metabolism*
D004573:Electrolytes; D014867:Water; D006170:Gum Arabic; D010695:Phlorhizin; D005947:Glucose