Na⁺ dependent acidification recovery in rat caput epididymal epithelium.

<p>A: Representative record chart showing involvement of Na⁺ in the HCO₃⁻ mediated recovery for NH₄Cl induced acidification in rat caput epididymal epithelium. The HEPES-KH solution containing 40 mM NH₄Cl caused intracellular alkalization. Washing the NH₄Cl with Naf-HEPES-KH solution would arouse intracellular acidification with no remarkable recovery. When the perfusion solution was changed into Naf-HCO₃⁻-KH solution, the recovery was still depressed. When the perfusion solution was changed into normal KH solution, the intracellular acidification recovered to basal level; B: The summary of the results showing the effect of Na⁺ on HCO₃⁻ mediated intracellular acidification recovery. HCO₃⁻ mediated intracellular acidification recovery in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0022283#pone-0022283-g002" target="_blank">Fig. 2B</a> is set as control group. Data are expressed as the change of the pH value per minute. NH₄Cl, 40 mM NH₄Cl; ami, 1 mM amiloride; Naf, Na+ free; Ctl, control; Columns and error bars are mean ± S.E.M. (n = 3; ** P<0.01 vs Ctl).