[Oxygen supply of middle- and inner ear in experimental tubar occlusion (author's transl)]

1. The mucosa of the middle ear is not only supplied with oxygen from the blood but also from the air space of the middle ear. 2. Under physiological conditions, the perilymph is supplied partially with oxygen from the tympanic cavity. When the PO2 in the middle ear falls below 57 mm Hg, a net diffusion flux of oxygen from the perilymph to the middle ear induces a loss of oxygen from the inner ear. 3. A negative pressure of 25 mm Hg generated in the middle ear, causes a transudate. Subsequently, slight disturbances of microcirculation should occur in the mucosal membrane (pO2-histogram). More pronounced negative pressure lead to very distinct disturbances of microcirculation and local oxygen supply.