Summary
The effects of artificial perilymph at various pH levels and osmolarities on the endocochlear potential (EP) were investigated in a guinea pig model. In 47 ears, the mean EP was 74.5 ± 0.5 mV in the second turn of the cochlea before perilymphatic perfusion. The artificial perilymph with a pH ranging from 5 to 9 and tonicity less than 1.25 (osmolarity, 345 mosmol/1) did not alter the EP when testings were recorded for at least 1 h. However, after the start of a perfusion with a pH less than 4, the EP declined gradually but recovered to the pre-perfusion level rapidly when the perfusion was stopped. The artificial perilymph with a pH over 10 decreased the EP considerably but showed no recovery, even after cessation of the perfusion. Tonicity more than 1.35 (osmolarity, 372.6 mosmol/1) also decreased the EP, with this decrease paralleling further increases in the tonicity used. From these data, we have concluded that a perilymph perfusate with a pH from 5 to 9 and an osmolarity less than 350 mosmol/I can be used in animal testing without any noxious effects on the EP.
Similar content being viewed by others
References
Konishi T (1978) Ion transport in the cochlea of guinea pig. II. Chloride transport. Acta Otolaryngol (Stockh) 86:176–184
Makino K (1983) Effects of potassium canrenoate on the endocochlear potentials. Audiol Jpn 26:311–312
Misrahy GA (1958) Measurement of the pH of the endolymph in the cochlea of guinea pigs. Am J Physiol 194:393–395
Sohmer H (1967) Effect of the osmotic pressure of solutions applied to the cochlea of guinea pigs and cats on cochlear potentials. Acta Otolaryngol (Stockh) 64:55–64
Author information
Authors and Affiliations
Additional information
Offprint requests to: S. Wakizono
Rights and permissions
About this article
Cite this article
Wakizono, S., Komune, S. & Uemura, T. Susceptibility of the endocochlear potential to pH and osmolarity changes in the perilymph of the cochlea in the guinea pig. Eur Arch Otorhinolaryngol 247, 97–99 (1990). https://doi.org/10.1007/BF00183176
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00183176