Fig. 11.

APOL1-associated ion flux and current are inhibited by acidic extracellular pH. A and B: extracellular protons inhibit ⁴⁵Ca²⁺ uptake (n = 20; A) and ³⁶Cl⁻ uptake (n = 10–20; B) by oocytes injected 72 h earlier with 10 ng APOL1 cRNA and subsequently maintained in HiK MBS. *P < 0.05. C and D: extracellular protons inhibit the increased two-electrode voltage clamp current in oocytes maintained 72 h in HiK MBS after injection with 10 ng APOL1 cRNA (n = 11; C), but inhibit only minimally the smaller currents recorded in uninjected oocytes (n = 7; D). Values are means ± SE. *P < 0.05 by Mann-Whitney test. **P < 0.001 by t-test.