Figure 4. Whole-cell currents in neutrophil granulocytes induced by high ADPR concentrations and the effects of intracellular Ca²⁺.

The pipette solution contained 30 μM ADPR (A–C) or 100 μM ADPR (D) in the presence of either a low (<10 nM) or high (1 μM) Ca²⁺ concentration. The Na⁺ in the bath was replaced by the impermeable cation NMDG during time periods indicated by horizontal bars in (A, D). Current–voltage relations in low Ca²⁺ (B) and in high Ca²⁺ (C) were recorded with voltage ramps at time points indicated with numbers in (A). Note the different scaling of the ordinate in (B, C).