Figure 3.

K_IR current in cerebral arterial smooth muscle cells. Whole-cell K⁺ current was measured in isolated smooth muscle cells bathed in a high K⁺ solution (60 mM) using a voltage ramp protocol (−100 to +20 mV) in presence and absence of BaCl₂ (1 µM–1 mM). Representative whole-cell current recording (a) and Ba²⁺-subtracted currents (b). Summary plots (n = 7) illustrate the effect of Ba²⁺ (1 µM–1 mM) on whole-cell current (c) and on peak inward current at −100 mV (d). Ba²⁺ induces a concentration-dependent inhibition of K_IR current (e, n = 7) at both −100 mV (IC₅₀ = 7.70 ± 0.85 µM) and −60 mV (IC₅₀ = 6.78 ± 0.67 µM). Data are means ± SE. **Significant difference from control.