title: Permeability to potassium of the endolymph-perilymph barrier and its possible relation to hair cell function.
abstract: The endocochlear potential and potassium concentrations in endolymph and perilymph were simultaneously measured in the basal turn of the guinea pig cochlea with double-barreled K+ selective electrodes. The K+ conductance and K+ permeability coefficient of the endolymph-perilymph barrier were calculated from the rate of change of endolymph K+ concentration relative to the K+ electrochemical potential difference recorded during permanent anoxia. When anoxia was induced in guinea pigs treated with kanamycin, the rate of decline of the electrochemical potential difference for K+ between the endolymph and perilymph was reduced when compared to normal guinea pigs. In guinea pigs exposed to broad band noise at 115 dBA for periods from 11-15 days, the rate of decline of the electrochemical potential difference for K+ across the endolymph-perilymph barrier was reduced but not to the extent found in guinea pigs treated with kanamycin. The K+ conductance and K+ permeability coefficient of the endolymph-perilymph barrier showed substantial decreases in noise exposed and kanamycin treated guinea pigs, as compared to normal guinea pigs. The magnitude of decrease of K+ permeability of the endolymph-perilymph barrier by noise or kanamycin was correlated with suppression of the maximum output of the cochlear microphonic.
mesh_terms: D000818:Animals; D002463:Cell Membrane Permeability / Q000187:drug effects; D003055:Cochlear Microphonic Potentials / Q000187:drug effects; D004710:Endolymph / Q000187:drug effects / Q000378:metabolism*; D006168:Guinea Pigs; D006198:Hair Cells, Auditory / Q000187:drug effects / Q000502:physiology*; D006317:Hearing Loss, Noise-Induced / Q000378:metabolism; D000860:Hypoxia / Q000378:metabolism; D007612:Kanamycin / Q000494:pharmacology; D007761:Labyrinthine Fluids / Q000378:metabolism*; D010498:Perilymph / Q000187:drug effects / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*
chemical_list: D007612:Kanamycin; D011188:Potassium