Skip to main content
. 2006 Aug 10;576(Pt 2):417–425. doi: 10.1113/jphysiol.2006.117176

Figure 4. Effects of extracellular Ca2+ on the V-ATPase current.

Figure 4

A, time courses of the changes in the H+ currents at 0 mV in the presence of 10–40 mm Ca2+ and subsequent application of 200 nm bafilomycin A1 (upper panel) and the recovery following washing of 40 mm Ca2+ (lower panel). The abscissa shows the time after rupture of the patch membrane. B, Ca2+-sensitive currents. The current densities (at 0 mV) were 0.025 ± 0.006 pA pF−1 (n = 7) for 10 mm Ca2+ and 0.058 ± 0.017 pA pF−1 (n = 8) for 40 mm Ca2+. In cells treated with 200 nm bafilomycin A1 (+ Bafilo), Ca2+-sensitive currents were reduced significantly, to 0.009 ± 0.012 pA pF−1 (n = 5) *P < 0.05. C, bafilomycin A1 (200 nm)-sensitive currents in the presence of different concentrations of extracellular Ca2+: 0.104 ± 0.012 pA pF−1 (n = 25) for 1 mm; 0.068 ± 0.011 pA pF−1 (n = 4) for 5 mm; 0.055 ± 0.019 pA pF−1 (n = 5) for 10 mm; and 0.036 ± 0.008 pA pF−1 (n = 8) for 40 mm Ca2+. pHo/pHi was 7.3/5.5. The pipette contained 5 mm ATP. **P < 0.01 compared with the data at 1 mM Ca2+.