Endolymph formation in the inner ear of pigeons.
The endolymphatic space of pigeons was studied by using double-barrelled electrodes with a potassium liquid ion exchanger. The K+ activity of the endolymph was 155 mM in the cochlea and 133 mM in the ampulla, respectively. Positive DC potential in the cochlea (+14.5 mV) was much lower than in guinea pigs (+80 mV) whereas in the ampulla of pigeons the DC potential (+7.4 mV) was 2 times higher than that of guinea pigs (+3.9 mV). General application of ethacrynic acid in pigeons induced a weak change in DC potential and no typical intercellular edema in the cochlea and ampulla. Local application of ethacrynic acid and ouabain in the cochlea and ampulla of pigeons induced a negative DC potential of between -30 and -40 mV. This negative DC potential was higher than the anoxia-induced negative potential. Short hypoxia during a drug-induced DC potential resulted in a decrease in DC potential above the diffusion potential. Below the diffusion potential additional hypoxia increased the DC potential independent of the cause of intoxication.
D000818:Animals; D003051:Cochlea / Q000502:physiology; D003055:Cochlear Microphonic Potentials; D010856:Columbidae / Q000502:physiology*; D004710:Endolymph / Q000502:physiology*; D004976:Ethacrynic Acid / Q000494:pharmacology; D006168:Guinea Pigs; D000860:Hypoxia / Q000503:physiopathology; D007761:Labyrinthine Fluids / Q000502:physiology*; D010042:Ouabain / Q000494:pharmacology; D010498:Perilymph / Q000502:physiology; D011188:Potassium / Q000378:metabolism; D013316:Stria Vascularis / Q000502:physiology
D010042:Ouabain; D004976:Ethacrynic Acid; D011188:Potassium