Sodium pumps and galactose transfer in the short-circuited small intestine

In a short-circuited preparation of rat jejunum, there are two sodium pumps, one electrogenic and the other neutral. When energy sources are limited, the total sodium transfer is limited. In the presence of a non-metabolized actively transferred hexose, the electrogenic pump is preferentially used. The neutral sodium pump is only able to function when additional energy is available.