Endolymphatic Oxygen Tension in the Cochlea of the Guinea Pig

Abstract
Oxygen tension of the endolymph in the scala media of the guinea pig cochlea was measured using a micro‐polarographic technique. Near the stria vascular is the oxygen tension was 55 to 70 mm Hg. Deeper in the scala media it decreased gradually to 16 to 25 mm Hg.Effects of sound, hypoxia, hyperoxia, and hypercapnea were studied. Oxygen tension decreased with hypoxia and sound, and it increased with hyperoxia and hypercapnea. A technique to check the integrity of a metallic‐plated microelectrode is described.