Relation between microvilli membrane potential and glucose transport capacity of rat small intestine.

Transepithelial electrical potential differences induced by glucose were measured in rat small intestine under conditions of experimental diabetes, application of corticosteroids, adrenalectomy, and inhibition of adrenocortical functions. A close linear correlation between the capacity of monosaccharide absorption and the transepithelial potential difference was found. Microelectrode studies indicated that glucose-induced alterations of the transepithelial potential difference are due to depolarization of the potential difference across the microvilli membrane. Changes in the potential difference across the basolateral plasma membrane were not detectable after addition of glucose.