Figure 1. Stimulation of whole-cell current and intracellular Ca²⁺ by exogenous ATP.

A, stimulation of whole-cell current by exogenous ATP (100 μM) in mIMCD-K2 cells in the standard bath solution. Data are shown for the membrane potential held at 0 mV (200 ms) and alternated at ±80 mV for 500 ms every 2 s. B, stimulation of whole-cell current by exogenous ATP (100 μM) when bath Cl⁻ was reduced 10-fold. Other details as for A.C, stimulation of intracellular Ca²⁺ by ATP (100 μM). Cells in standard bath solution were superfused with ATP-containing solution. Intracellular Ca²⁺ is expressed as the ratio of emissions at 340 nm/380 nm; records are displaced to show 3 separate experiments.