Effects of Salicylate on Shape, Electromotility and Membrane Characteristics of Isolated Outer Hair Cells from Guinea Pig Cochlea

Abstract

A reversible tinnitus and hearing loss have long been known to result from large doses of salicylate. Cochlear electrophysiology and otoacoustic emission studies suggest that the drug may interfere with outer hair cell electromotility. Exposure of isolated outer hair cells to sodium salicylate concentrations ranging from 0.05 to 10 mM reveals a dose dependent, reversible loss of turgidity and dimunition of electromotility. There was also a change in membrane conductance with salicylate superfusion that occurred later in time from the onset of shape and electromotility changes. There was no evidence of dose dependence for the change in membrane conductance, nor was the change reversible. the changes in shape and electromotility that we observe in vitro may impair cochlear partition movements in vivo and could account, at least in part, for the salicylate-induced hearing loss and effects on otoacoustic emissions.

Key Words:

• aspirin
• hearing loss
• membrane conductance
• otoacoustic emissions
• turgor
• whole cell recording
• morphometric analysis