Fig. 4. Calcium levels in endolymph in the presence of chemical gradients of calcium across the saccular epithelium of perfused inner ear of trout. (A) Proximal endolymph, (B) distal endolymph. The value at time 0 min (hatched colums) is the calcium content of endolymph before starting the perfusion. The inner ear was then perfused with a Ringer solution containing different concentrations of calcium (0.19 mmol l^-1, white bars; 3.22 mmol l^-1, grey bars; 4.40 mmol l^-1, black bars). Endolymph was sampled in the left saccule at 35 min and in the right saccule at 70 min. N values are given in parentheses. NS, not significant; ^*P<0.01; ^**P<0.001 in comparison with control values.