Meta-Biol

• Pathways

The plasma membrane-associated transport proteins SVCT1 and SVCT2 (encoded by SLC23A1 and SLC23A2 respectively) are each capable of mediating the uptake of one molecule of ascorbate (AscH-) and two sodium ions from the extracellular space to the cytosol (Daruwala et al. 1999, Rajan et al. 1999, Wang et al. 1999). In the body SVCT2 is expressed in most tissues, while SVCT1 is largely confined to epithelial cells (Liang et al. 2001). SVCT2 may mediate fetal uptake of ascorbate from the maternal circulation (Rajan et al. 1999). The transporters responsible for its uptake from the small intestine and for its release from enterocytes into the circulation have not been identified, although both SVCT1 and 2 are expressed in intestinal cells.