Fig. 6.

Effect of K⁺ channel blockers on initial rate of DC-EBIO-enhanced ⁸⁶Rb efflux in KCNN4b- and KCNNc + BKβ1 cRNA-injected oocytes. ⁸⁶Rb loading and effluxes were performed as described in materials and methods. ⁸⁶Rb efflux was measured for 5 s by placing the KCNN4b (A) and KCNN4c + BKβ1 (B) cRNA-injected oocytes in K⁺-free medium and considered 100% (Control). ⁸⁶Rb efflux was also measured in the presence of 5 μM TRAM-34, 1 μM clotrimazol (CLT), 5 mM Ba²⁺, 100 nM iberiotoxin (IbTX), 10 nM apamin (APA), and 50 μM chromanol 293B (Chr 293B). When Ba²⁺ was present, Na⁺ concentration was adjusted to maintain osmolarity. When compared with KCNN4 cRNA-injected oocytes, PBS and BKβ1 cRNA-injected oocytes exhibited <2% ⁸⁶Rb efflux (data not shown). *P < 0.001 compared with control.