Cholesterol effect on KCa1.1 current.

<p><b>A</b>. Voltage-dependent KCa1.1 current recorded in hKCa1.1-HEK 293 cells with the voltage protocol (<i>inset</i>) in cells treated with cholesterol depletion (MβCD) or cholesterol enrichment (MβCD-cholesterol). <b>B</b>. <i>I-V</i> relationships of hKCa1.1 current in control (n = 19), cholesterol depletion (n = 16, *<i>P</i><0.05 or **<i>P</i><0.01 vs. control at 0 to +60 mV) or cholesterol-enrichment (n = 11, <i>P</i> = NS vs. control). <b>C</b>. Percentage values of hKCa1.1 current at +60 mV in control (n = 16), cholesterol depletion (n = 19, **<i>P</i><0.01 vs. control) or cholesterol enrichment (n = 11, ^##<i>P</i><0.01 vs. MβCD alone). <b>D</b>. Single channel activity of hKCa1.1 channels recorded in cell-attached mode at +60 mV in cells treated with 5 mM MβCD or MβCD-cholesterol. The labels C, O₁ and O₂ indicate the close level, 1^st and 2^nd opening levels of the channel. <b>E</b>. Histograms of open probability of hKCa1.1 single channels in cells treated without (control) or with cholesterol depletion (MβCD). <b>F</b>. Mean values of open probability of hKCa1.1 channels in control (n = 8), MβCD (n = 6), and MβCD-cholesterol (n = 6, *<i>P</i><0.05 vs. control). <b>G</b>. Conductance of hKCa1.1 channels in control, MβCD, and MβCD-cholesterol (n = 6–8, <i>P</i> = NS vs. control).