Cholesterol and active analogues decrease BK Po both by shortening mean open times and lengthening mean closed times. Scatter graphs showing individual mean open (A) and mean closed (C) times of cbv1 channels reconstituted into control or monohydroxysterol-containing bilayers. For A and C: *, significantly different from control (P < 0.05); **, significantly different from control (P < 0.01). Averaged mean open and mean closed times under different conditions are given in B and D. These data show that cholesterol-, coprostanol-, and cholestanol-induced decrease in cbv1 Po is determined by the ability of these steroids to shorten mean open times and lengthen mean closed times. Linear regression was conducted with Origin 7 Software (OriginLab). r, regression coefficient.