Na+-dependent, electroneutral L-ascorbate transport across brush border membrane vesicles from guinea pig small intestine.
In brush border vesicles from guinea pig small intestine L-ascorbate transport is Na+-dependent and electroneutral (in the presence of Na+, as shown by its lack of response to either positive or negative delta psi across the membrane). L-Ascorbate transporter has the kinetic characteristics of a mobile carrier (Km for L-ascorbate, 0.3 mM). D-Isoascorbate (erythorbate) seems to be another, but poorer, substrate of the same transporter. L-Ascorbate transport is subjected to heterologous inhibition by D-glucose.
D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D006168:Guinea Pigs; D007408:Intestinal Absorption / Q000187:drug effects; D007421:Intestine, Small / Q000378:metabolism*; D007536:Isomerism; D007700:Kinetics; D008564:Membrane Potentials; D008871:Microvilli / Q000187:drug effects / Q000378:metabolism*; D012964:Sodium / Q000494:pharmacology*; D013329:Structure-Activity Relationship
D012964:Sodium; D001205:Ascorbic Acid