Ion Transport in the Cochlea of Guinea Pig:II. Chloride Transport

Abstract

The ⁻CI transport across the endolymph-peri-lymph barrier in guinea pigs was studied by perfusing the perilymphatic space with artificial perilymph containing ³⁶CI and measuring the uptake of ³⁶CI in the endolymph. In normal animals no marked difference in ⁻CI concentration was found between the endolymph and perilymph. The data showed that the uptake of ³⁶CI in the endolymph could be represented by a simple exponential function of the perfusion time, the rate constant being 0.01 min⁻¹. The concentration of ³⁶CI in the endolymph was greater with perfusion of the scala vestibuli than with perfusion of the scala tympani, indicating that Reissner's membrane is more permeable to ⁻CI than the rest of the endolymph-perilymph barrier. Anoxia and local application of ouabain decreased the ⁻CI concentration and ³⁶CI uptake in the endolymph. Our results imply that the endocochlear potential is the principal driving force for unidirectional flux of ⁻CI from perilymph to endolymph.