In this study, we examined the release of dopamine from gunea-pig cochlea, with a liquid scintillation counter, using in vitro superfusion technique in microvolume chambers. After dissecting of the cochlea from the bulla tympani (revealing the organ of Corti), tissues were introduced in microvolume chambers and superfused with thermoregulated and 100% O2 saturated perilymph-like solution. The labelled [7.8-3H] dopamine release was determined under electrical and chemical stimulation. Ischaemia, glucose deprivation and acidosis caused a significant increase of dopamine release. The results were the same under chemical stimulation, providing evidence of transmitter role of dopamine between lateral olivocochlear bundles and type I afferent fibres. It provides also evidence of protective role of dopamine against acoustic nerve damage caused by acoustic trauma, ischaemia or acidosis.