Aboral changes in D-glucose transport by human intestinal brush-border membrane vesicles.
D-Glucose transport was investigated in isolated brush-border membrane vesicles from human small intestine. Characteristics of D-glucose transport from the jejunum were compared with that in the mid and terminal ileum. Jejunal and mid-ileal D-glucose transport was Na+-dependent and electrogenic. The transient overshoot of jejunal D-glucose transport was significantly greater than corresponding values in mid-ileum. The terminal ileum did not exhibit Na+-dependent D-glucose transport, but did exhibit Na+-dependent taurocholate transport. Na+-glucose co-transport activity as measured by tracer-exchange experiments was greatest in the jejunum, and diminished aborally. We conclude that D-glucose transport in man is Na+-dependent and electrogenic in the proximal intestine and directly related to the activity of D-glucose-Na+ transporters present in the brush-border membranes. D-Glucose transport in the terminal ileum resembles colonic transport of D-glucose.
D001692:Biological Transport; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007082:Ileum / Q000378:metabolism; D066298:In Vitro Techniques; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000378:metabolism; D007583:Jejunum / Q000378:metabolism; D008871:Microvilli / Q000378:metabolism; D013656:Taurocholic Acid / Q000378:metabolism
D013656:Taurocholic Acid; D005947:Glucose