Figure 3.

Inhibition of calmodulin or CaMKII slows the decay of I_Cl(Ca). Dialysis of the calmodulin inhibitor W7 (Upper Left) slowed the rate of I_Cl(Ca) decay, resulting in a similar rate of current and [Ca²⁺]_i decay (Inset). Dialysis of the CaMKII inhibitor KN93 (Upper Right) or the CaMKII substrate antagonist (50 μM, Lower Left) had an equivalent effect. In contrast, dialysis of H7 (Lower Right) at a concentration predicted to substantially inhibit PKC, PKA, and PKG activity did not slow the rate of I_Cl(Ca) decay. All solutions contained 1 mM ATP, and cells were dialyzed for 5 min before exposure to caffeine; cells were clamped at −60 mV.