Mechanosensitive Channel Currents Recorded in Rat Brain Microvascular Endothelial Cells with Whole-cell Mode

Using the whole-cell patch-clamp technique, delayed outward currents were recorded in rat brain microvascular endothelial cells(RBMECs), which were nearly completely inhibited by extracellular TEA-Cl at a concentration of 20 mmol/L. Whole-cell currents were elicited by 2 100 ms depolarizing voltage pulses applied every 7 s between -100 mV to +90 mV, with 10 mV increment, from a holding potential of -100 mV. The currents were similar with delayed rectified K(+) currents (IKv)which were inhibited in a concentration-dependent manner by both application of TEA-Cl, with an IC(50) approximately 2.0 mmol/L. In the presence of mechanical force, outward currents were increased in amplitude as compared with controls. These mechanical force-induced currents were also defined as IKv, which were different from previous described mechanosensitive currents induced by mechanical force with characteristic of inward rectifier.