Fig. 5. 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. Values at time 0 min (hatched columns) are the calcium content of endolymph before starting the perfusion. The inner ear was then perfused with a Ringer solution containing 3.23 mmol l^-1 calcium and 35 min later endolymphs were sampled in the left saccule. The perfusion was then either continued with the same [Ca]-Ringer, or with different concentrations of Ca-Ringer (0.19 mmol l^-1, white bars; 3.22 mmol l^-1, grey bars; 4.40 mmol l^-1, black bars) and at t=70 min the endolymph was sampled in the right saccule. N values are given in parentheses. NS, not significant; ^*P<0.01; ^**P<0.001, for comparison between t=35 min and t=70 min.