Galactose transport across the hamster small intestine: the effect of sodium electrochemical potential gradients.

1. Measurements of galactose unidirectional fluxes across the isolated mucosa of the hamster small intestine were made under a variety of experimental conditions designed to investigate the interrelationships between galactose transport, the sodium ion and electrical potentials.2. Galactose transport was inhibited by lowering the sodium concentration in the mucosal and/or serosal solutions and by increasing the p.d. across the tissue. This inhibition of galactose transport was judged to be irreversible.3. Transport was unaffected by decreasing the p.d. across the tissue.4. These results are discussed in relation to the model proposed to explain galactose transport across the intestine.