The effect of different Na+-substitutes on the intestinal absorption of glucose

Abstract

The effect of the replacement of Na+ by Tris, K+, Li+ or mannitol on the intestinal absorption of 2.77 mM glucose is studied in vivo in the rat.

On using these substitutions minimal inhibition is seen with Tris and inhibition increases progressively with K+, Li+ and mannitol respectively. On a return to solutions with 154 mEq Na+/1, inhibition practically disappears if the substitute is Tris. The recovery is also high in the case of K+, whereas with Li+, and more so with mannitol, a certain period of time is necessary to attain normal levels of absorption. Inhibition of absorption by a substitution for Na+ cannot be explained as due to the mere absence of this cation but also to the intervention of other factors depending on the properties of the replacement substances, which affeci: the epithelium with a variable intensity for more time or less. The greatest alterations are seen with mannitol.