Abstract
Divalent heavy metal ions, cobalt, manganase, nickel were applied to guinea-pig cochlea by perilymphatic perfusion method. Each heavy metal ion was dissolved in artificial perilymph at the concentrartions of 1, 10, 100mM, At 1mM, peak amplitude of CM decreased to about 80%, although EP showed little change. During 60-90 min perfusion with 10mM metal ions, EP decreased from +80mV to +50-+20mV, and concomitantly peak CM decreased by 20-80%. At 100mM, decreases of both EP and CM were rapid and magnified than those at 10mM. The interesting finding was that EP increased transiently by about 10mV prior to the start of decreased. The results indicate that Ca dependent ion transport system in stria vascularis cells contributs to generation of EP.
