Intermediate Endocochlear Potential Levels Induced by Hypoxia

Abstract

It seems that the positive potential of the scala media (endocochlear potential [EP]) and the high potassium concentration in the endolymph are generated and maintained by an electrogenic pump. In order to study its properties, the EP was measured in cats ventilated with low oxygen gas mixtures (2.25-10%). It was found that the EP could be maintained at intermediate levels which were more or less linear functions of blood oxygen tension (25-60 mmHg), showing that the pump can operate on intermediate levels. This hypoxic preparation may contribute to the study of cochlear blood flow.