Electrochemical aspects of cations in the cochlear hair cell of the chinchilla: a cellular model of the ion movement.
The dc potential and ion composition (K+, Na+, and Ca++) in the hair cells of the cochlea were examined using ion-selective microelectrodes. The K+, Na+, and Ca++ concentrations were 124.0 +/- 29.8 mM, 6.9 +/- 4.1 mM, and 1.7 +/- 1.4 microM in the hair cells, respectively. The electrochemical potential gradients for K+, Na+, and Ca++ across the apical membranes of the hair cells were calculated to be 160.0 +/- 29.8 mV, 87.6 +/- 27.0 mV, and 194.4 +/- 35.2 mV, respectively. Those for K+, Na+, and Ca++ across the basolateral membranes of the hair cells were -12.6 +/- 33.3 mV, 126.8 +/- 28.3 mV, and 170.8 +/- 30.1 mV, respectively. These findings were discussed in light of the transport mechanism necessary to maintain the ionic composition of hair cells.
Department of Otolaryngology, University of Minnesota Medical School, Minneapolis.
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Ikeda
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Morizono
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002682:Chinchilla; D004563:Electrochemistry; D006198:Hair Cells, Auditory / Q000378:metabolism*; D007473:Ion Channels / Q000378:metabolism*; D007761:Labyrinthine Fluids / Q000378:metabolism*; D008564:Membrane Potentials; D008839:Microelectrodes; D009925:Organ of Corti / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism
D007473:Ion Channels; D012964:Sodium; D011188:Potassium; D002118:Calcium