Fig. 4.

Amiloride-sensitive transepithelial current measurements in Xenopus 2F3 cells after inhibition of CaMKII with KN93. Xenopus 2F3 cells grown on permeable supports were maintained in culture for 10 days to allow for the formation of tight junctions and the generation of measurable voltages and resistances across the monolayers. The pharmacological inhibitor of CaMKII, KN93 (0.5 μM) was applied to the apical side of Xenopus 2F3 cells at time 0 after recording of baseline voltage and resistance. Transepithelial voltages and resistances were used to calculate the current across the monolayers. A transient increase in transepithelial current was observed after 1 h of application of KN93. The increase in transepithelial current was sustained for an additional hour. At the end of the experiment, amiloride (0.5 μM) was applied to the apical side of the cells as a control (not shown).