Effect Of Potassium Deficiency On Cochlear Potentials And Cation Contents Of The Endolymph

Abstract

The scala vestibuli and/or scala tympani in anesthetized guinea pigs was perfused with potassium-free solution. Cochlear microphonics (CM), summating potential (SP), action potential (AP) and endocochlear potential (EP) were recorded before, during, and after the perfusion. The sodium and potassium contents in the endolymph were also determined. Perfusion of both scala vestibuli and tympani with control solution did not produce appreciable changes in electrical responses or sodium and potassium content in the endolymph. Perfusion of the perilymphatic space with potassium-free solution caused significant suppression of EP and AP. The CM was also reduced and accompanied by increase of the positive SP. These changes were reversible. The measurement of potassium and sodium content in the endolymph indicated that potassium deficiency in the perilymph resulted in significant increase of sodium and decrease of potassium content. The role of potassium ions in the perilymph is discussed.