Calcium transport in the endolymphatic space of cochlea and vestibular organ.
Ca++ concentrations and d.c. potential within the endolymphatic space of the cochlear duct and the semicircular canal following acute anoxia or ethacrynic acid intoxication (100 mg/kg i.v.) were measured by means of double-barrelled microelectrodes. Ionic calcium content and d.c. potential were found to change in a roughly biphasic fashion after either intervention. The maximal increase in Ca++ concentration coincided with the decline in the d.c. potential, which after a rapid decline finally reached and maintained negative voltages. This phenomenon was more pronounced in the cochlear part than in the semicircular canal. A model of calcium homeostasis is proposed in an attempt to reconcile the data presented with earlier evidence.
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D003051:Cochlea / Q000187:drug effects / Q000378:metabolism*; D004710:Endolymph / Q000187:drug effects / Q000378:metabolism*; D004976:Ethacrynic Acid / Q000494:pharmacology; D006168:Guinea Pigs; D006706:Homeostasis / Q000187:drug effects; D000860:Hypoxia / Q000378:metabolism; D007761:Labyrinthine Fluids / Q000378:metabolism*; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D014722:Vestibule, Labyrinth / Q000187:drug effects / Q000378:metabolism*
D004976:Ethacrynic Acid; D002118:Calcium