Figure 2.

Effects of calixarenes on I_C1,swell. (A) Current traces in response to voltage steps to potentials between −10 and +110 mV (step increment is 10 mV) applied from a holding potential of −30 mV. Traces were recorded after full activation of I_{C1, swell} by applying a 25% hypotonic solution under control conditions, and in the presence of 30 μM of either 4-sulphonic-calix[4]arene, -calix[6] arene or -calix[8]arene. The traces at the right were obtained after washout and show the reversibility of the effects. (B) Inhibitions, expressed as a percentage reduction of the currents at the end of the voltage steps, as a function of the applied voltage calculated from the traces in (A). The inhibition of the current by 4-sulphonic-calix[4]arene is most prominent at small positive potentials, but declines at more positive potentials. The effect is much less pronounced for the other two calixarenes.