H⁺, K⁺-ATPase is not Involved in Endolymph pH Homeostasis

Abstract

In endolymph, the calculated electrochemical gradients suggest the presence of active transport of H⁺ and K⁺. The presence of H⁺, K⁺-ATPase, an active transporter that mediates the exchange of intracellular H⁺ for extracellular K⁺, was investigated using reverse transcription-polymerase chain reaction on rat microdissected inner ear tissues. Distal colon and kidney were used as positive controls. The two H⁺, K⁺-ATPase colonic or gastric isoforms were not detected in the rat cochlea and endolymphatic sac. This result suggests that H⁺, K⁺-ATPase is not involved in H⁺ and K⁺ endolymph homeostasis.

• Acid Base Equilibrium Cochlea Endolymphatic Inner Fluids Potassium