Regulation and adaptation of shear stress-sensitive ion channels in vascular endothelial cells

This study investigated factors regulating SSK and SSCI current activation and the adaptation of these currents in chronically-sheared BAECs using whole-cell patch-clamp recordings. In unsheared BAECs, steady flow increased SSK and SSCl conductance by 14±1% and 76±19%, respectively. Pretreatment of the cells with 0.5 μg/ml PTX 3 hours abolished the flowinduced SSK and SSCl conductance increase. Direct and sustained G protein activation with 1 mM GTP-γS without flow transiently activated G proteinregulated currents. Subsequent exposure of these cells to steady flow did not significantly increase SSK or SSCl conductance, suggesting that activation of G proteins is necessary to induce these currents. Flow also increased SSK and SSCl conductance in chronically-sheared, flow-elongated BAECs.