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. 2010 Jan 6;5(1):e8602. doi: 10.1371/journal.pone.0008602

Figure 1. Effects of gluconate and other anions on CaV1.2 currents.

Figure 1

A. CaV1.2 currents (short N-terminal isoform) were progressively inhibited by replacing increasing amounts of extracellular chloride with gluconate. 5 mM Ba2+ was used as a charge carrier and currents were evoked by a ramp voltage protocol (−90 to +60 mV, 0.5 mV/ms). Traces show IBa recorded in control conditions and after 2 min superfusion with solutions containing increasing concentrations of gluconate (14 mM, 28 mM, 68 mM, and 135 mM). Leak currents were removed by subtracting the ohmic conductance measured below IBa threshold. B. Increasing gluconate concentration caused a concentration-dependent increase in inhibition of the peak amplitude of CaV1.2 currents. A gluconate concentration of 14 mM caused 20.1±4.4% (N = 14) inhibition whereas 135 mM gluconate caused 82.9±2.9% inhibition (N = 28). C. Replacing 14 mM Cl− with equimolar perchlorate increased CaV1.2 currents (18.7±5.8%, N = 6) but further increases in perchlorate concentration caused a concentration-dependent inhibition of CaV1.2 currents with −96.8±0.9% inhibition (N = 7) at a perchlorate concentration of 135 mM. D. Bar graph comparing effects of replacing 135 mM Cl− with equimolar quantities of perchlorate (N = 7), gluconate (N = 28), thiocyanate (N = 8), nitrate (N = 9), iodide (N = 10) and bromide (N = 9). All of these experiments were performed using α1/β2a/α2δ.