THE ION SELECTIVE FUNCTION OF THE EPITHELIUM OF THE MEMBRANOUS CANAL WALLS

Experiments on an isolated canal in the living animal have shown that blocking of the vascular supply results in a decrease in endolymph potassium concentration in this canal. In three hours of vascular blockade, the concentration falls to that of the surrounding perilymph. If the isolated canal has been filled with artificial perilymph and its vascular supply intact, the potassium concentration increases, indicating a selective ion-transport function of the canal epithelium which, under normal conditions, might contribute to maintaining the high potassium concentration of the endolymph in the canals as well as in the rest of the membranous labyrinth. (Author)