Hexose transport in the apical and basolateral membranes of enterocytes in chickens adapted to high and low NaCl intakes.

1. The effect of a low-NaCl diet (LS diet) on the properties of hexose transport across the brush-border and basolateral membranes of enterocytes from jejunum, ileum and rectum of the chicken was investigated. 2. In the brush-border membrane, LS adaptation had no effect on Km for alpha-methyl-D-glucoside while Vmax values were significantly reduced in the ileum and in the rectum. All Scatchard plots of specific [3H]phlorizin binding give a straight line, consistent with a single population of binding sites. Phlorizin binding vs. alpha-methyl-D-glucoside maximal transport rates showed a linear correlation. 3. In the basolateral membrane, the LS diet did not modify the Km for D-glucose but reduced the Vmax in the ileum and in the rectum. Scatchard plots of [3H]cytochalasin B binding support the view that there is a single transport system in this membrane. There was a linear correlation between cytochalasin B binding and D-glucose Vmax values. 4. The response of the chicken intestine to LS intake consists of a dramatic reduction in the number of glucose transporters in both apical and basolateral membranes of the rectum, an intermediate response in the ileum and no significant effects in the jejunum.