Figure 4.

K_Ca3.1 and K_Ca2 currents in HSAEpi cells. (A) Upper panel on left illustrates base line currents (1), immediately after membrane rupture (to achieve electrical access) and current–voltage relationship of K_Ca currents (2; n= 6 experiments) activated during cell dialysis with a pipette solution containing 3 µM [Ca²⁺]_free. To achieve maximal and stable channel activation, the K_Ca2/K_Ca3.1 channel opener SKA-31 (1 µM) was added to the bath solution. Upper panel on right: Currents were reduced by the K_Ca3.1 channel blocker TRAM-34 (1 µM, n= 4 experiments) and further reduced by additional application of the K_Ca2 channel blocker UCL1684 (1 µM, n= 4 experiments). (B) Summary data for K⁺-currents at 0 mV. Values are given as mean ± SEM; *P < 0.05, paired Student's t-test. (C) RT-PCR of K_Ca2 channels on HSAEpi cells and negative controls (non-reverse transcribed mRNA, -RT).