Fig. 5.

The LPI effect develops slowly, is sustained, reversible, and occurs in a concentration-dependent manner. a Representative single-channel recording in inside-out patch exposed to 1 and 3 μM LPI in the presence of 1 μM Ca²⁺ in the bath at a holding potential of −80 mV. Channel openings are shown as downward deflections. b Representative single-channel recording in inside-out patch exposed to 1 μM Ca²⁺ showing concentration-dependent activation of IK_Ca channel activity in response to bath application of 1, 3, and 10 μM LPI, which was reversible following 15 min of wash out of LPI. Channel openings are shown as downward deflections and bars from the left indicate the zero current level. c Statistical representation of the effect of 0.3 (n = 4), 1 (n = 5), 3 (n = 14), and 10 μM (n = 3) LPI on IK_Ca channel activity in the presence of 1 μM Ca²⁺ at a holding potential of −80 mV. *P < 0.05 vs basal NPo in the absence of LPI. d A representative amplitude histogram before (Control) and after exposure of excised patch to 3 μM LPI in the presence of 1 μM Ca²⁺. Data points were fitted by Gaussian fits. e Statistical representation of the effect of 3 μM LPI on IK_Ca channel activity in the presence of 10 μM (n = 4) and 1 μM Ca²⁺ (n = 14) at a holding potential of −80 mV