Figure 2.

TRAM-34 did not affect the function of BK-, K_V-, and K_ATP-channels in CASMC. (A) Whole-cell recordings of BK-currents in the presence or absence of TRAM-34 (10 μM) and blockade of BK-currents by selective BK-blocker iberiotoxin (IbTX, 100 nM). For K_Ca-activation CASMC were dialysed with a 140 mM K⁺ pipette solution containing 3 μM [Ca²⁺]_free. Bathing solution contained 4.5 mM K⁺. The experiment shown is representative of seven experiments with similar results. (B) Whole-cell recordings of K_V-currents in the presence or absence of TRAM-34 (10 μM) and blockade of K_V-currents by the K_V-blocker 4-aminopyridine (4-AP, 2 mM). CASMC were dialysed with a 140 mM K⁺-pipette solution containing 0.1 μM [Ca²⁺]_free. The experiment shown is representative of ten experiments with similar results. Bathing solution used for measurements of BK- and K_V-currents contained 4.5 mM K⁺. (C) Levcromakalim (LCRKM, 10 μM)-induced whole-cell currents through K_ATP-channels in CASMC in absence and presence of TRAM-34 (10 μM) and blockade of K_ATP-currents by the K_ATP-blocker glibenclamide (GLIB, 10 μM). CASMC were dialysed with a 140 mM K⁺-pipette solution containing 0.1 μM [Ca²⁺]_free and 5.3 μM [ATP]_free. Bathing solution contained 50 mM K⁺. Note that under these conditions and at holding potentials more negative than −26 mV, K_ATP currents were inwardly directed. The experiment shown is representative of eight experiments with similar results.