Figure 3.

Citrate potentiates ASIC1 currents in a concentration-dependent manner. A, Schematics: ASIC1 generates an inward current in response to increased extracellular protons. B, C, ASIC1-mediated currents were recorded in HEK293 cells. The cells were perfused in a bath solution, pH 7.4, containing no citrate, and each stimulus consisted of a 3 s exposure (at 30 s intervals) to a test solution, pH 6.5, except where pH 7.4 is indicated, that contained 0–30 mm citrate. In C, all test solutions had a pH of 6.5, and the concentrations of citrate in the test solutions are indicated on the x-axis; n = 4–5 independent HEK293 cultures, and error bars indicate the mean ± SEM.