Figure 1.

Effect of cholesterol depletion on whole-cell and single-channel VRAC induced by GTPγS. (A) Cholesterol levels in BAECs exposed to 5 mM MβCD and in control cells measured by GLC (n = 8–12; *P < 0.01). (B) Typical families of current traces recorded from individual cells dialyzed with 100 μM GTPγS elicited by application of linear voltage ramps materials and methods. The time-courses of VRAC current densities that developed in the same cells calculated by normalizing the maximal current amplitudes (+60 mV) of each individual ramp by the cell capacitance. (C) The activation rates and mean peak current densities of VRAC in cells treated with MβCD or control cells (n = 11–19). (D) Single-channel currents recorded in the outside-out excised patch configuration after a depolarization step from −60 to +140 mV. Examples of recordings when the channels were closing for a prolonged period of time (a) and the channels that flickered between the open and closed states (b). (E) Unitary conductances of the channels recorded in the membranes of the cells depleted of cholesterol and control cells.