The effect of kanamycin on experimentally induced endolymphatic hydrops.

In guinea pigs with endolymphatic hydrops 6 months after operation the DC potential had decreased from +80 mV to +50 mV, while the sodium activity had increased. The twofold increase in Na+ activity could explain the increased degree of endolymphatic hydrops. The K+ activity and Cl- activity were unchanged. However, endolymphatic hydrops could be produced in kanamycin-induced deaf guinea pigs after obliteration of the endolymphatic sac and duct. The physiological data on DC potential, K+, and Na+ activity were similar to those for non-treated animals. When the animals were treated with kanamycin 6 months after the development of endolymphatic hydrops, there was no effect on the morphological and functional changes compared to controls. The data suggest that regulation of the inner ear fluid occurs independent of an intact auditory system. The effect of aminoglycoside treatment in Ménière's disease cannot be explained by an effect on endolymphatic hydrops formation.