Abstract
Hexose and sodium can interact in the columnar epithelial cells of the intestine at various levels ( a ) in changing availability of energy, ( b ) at transport sites, ( c ) at the coupling mechanism between metabolism and transport or the coupling between Na transport and hexose transport. Glucose differs from other hexoses in being both transported and metabolized, and interactions with Na and glucose are therefore likely to be more complex than with other hexoses. The most interesting aspect of Na-hexose interaction is probably the mechanism of the coupling between Na and hexose transport. The Na gradient has been and remains still an attractive hypothesis, but other possibilities must be considered including the role of Na-sensitive ATPases.