Number of water molecules transported per glucose by the Na-glucose cotransporter SGLT1

Value 200 molecules of water/glucose
Organism Rabbit
Reference Ashmore J. Cochlear outer hair cell motility. Physiol Rev. 2008 Jan88(1):173-210. doi: 10.1152/physrev.00044.2006 p.195 left column top paragraphPubMed ID18195086
Primary Source [205] Loo DD et al., Passive water and ion transport by cotransporters. J Physiol. 1999 Jul 1 518(Pt 1):195-202 DOI: 10.1111/j.1469-7793.1999.0195r.xPubMed ID10373701
Method Primary source abstract: "The rabbit Na+-glucose (SGLT1) and the human Na+-Cl- -GABA (GAT1) cotransporters were expressed in Xenopus laevis oocytes, and passive Na+ and water transport were studied using electrical and optical techniques. Passive water permeabilities (Lp) of the cotransporters were determined from the changes in oocyte volume in response to osmotic gradients. The specific SGLT1 and GAT1 Lp values were obtained by measuring Lp in the presence and absence of blockers (phlorizin and SKF89976A)...Passive Na+ and water transport through SGLT1 were blocked by phlorizin with the same sensitivity (inhibitory constant (Ki), 3-5 microM)."
Comments P.194 right column bottom paragraph: "The calculated uptake of water is 175 molecules water per fructose transported. Similar water transport values for “water pumps” have been described for the Na-glucose cotransporter SGLT1 (primary source). In that case, 200 water molecules are transported per glucose."
Entered by Uri M
ID 117142