Abstract
The effects of adenosine 2'-diphosphate (ADP), which causes regional ischemia due to platelet micro-emboli, the inner ear oxygen tension (PO2) was studied in the guinea pigs. Two PO2-sensitive microelectrodes were inserted through a small hole into the endolymph of the cochlea and canal. The endolymph PO2 was simultaneously measured by a polarographic technique. The PO2 in the cochlea and canal during normal conditions was 60.3 (±12.2) and 61.3 (±14.7), respectively. When a small dose of ADP (0.1mg/kg) was injected into the carotid artery, endolymph PO2 decreased transiently. The decrease of cochlea PO2 tended to be larger than that of canal PO2. This finding indicats the higher vulnerability to emboli of the peripheral auditory organ.
