Shear activated channels in cell-attached patches of cultured bovine aortic endothelial cells
- 70 Downloads
We investigated the response of inward rectifier K+ (IRK) currents in bovine aortic endothelial cells (BAECs) to shear stress. Shear evoked reversible hyperpolarization in current clamped BAECs. Voltage clamped BAECs exhibited large inward and small outward whole cell K+ currents blocked by cesium and increased in amplitude by exposure to shear stress. The open state probability of IRK channels in cell-attached membrane patches was increased within minutes of exposure to shear stress. IRK channels in inside-out patches were activated by increases in [Ca2+]i from 10−7 to 10−6 mM. We demonstrate that shear stress induces hyperpolarization and gating of single channel and whole cell IRK currents in BAECs.
Key wordsPotassium channels membrane potential hyperpolarization endothelial cells shear stress inward rectifier ion channels calcium sensitivity
Unable to display preview. Download preview PDF.
- (1).Hille B (1992). Potassium channels and chloride channels. In Ionic channels of excitable membranes. Sunderland MA, Sinauer Associates, pp. 99–116.Google Scholar
- (2).Lansman JB, TJ Hallam, and TJ Rink (1987). Single stretch-activated ion channels in vascular endothelial cells as mechanotransducers. Nature 325:811–813.Google Scholar
- (3).Ling BN & WC O'Neill (1992). Calcium-dependent and Ca2+ permeable ion channels in aortic endothelial cells. Am J Physiol 263:H1827-H1838.Google Scholar
- (4).Nakache M & HE Gaub (1988). Hydrodynamic hyperpolarization of endothelial cells. Proc Nat Acad Sci 85:1841–1843.Google Scholar
- (5).Olesen SP, DE Clapham, and PF Davies (1988). Haemodynamic shear stress activated a K+ current in vascular endothelial cells. Nature 331:168–170.Google Scholar
- (6).Sauve R, L Parent, C Simoneau, and G Roy (1988). External ATP triggers a biphasic activation process of a calcium dependent K channel in cultured bovine aortic endothelial cells. Pflugers Archiv 412:469–481.Google Scholar
- (7).Shen J, FW Luscinskas, A Connolly, CF Dewey, and MA Gimbrone (1992). Fluid shear stress modulates cytosolic free calcium in vascular endothelial cells. Am J Physiol 262:C384-C390.Google Scholar
- (8).Silver MR & TE DeCoursey (1990). Intrinsic gating of inward rectifier in bovine pulmonary artery endothelial cells in the presence or absence of internal Mg2+. J Gen Physiol 96:109–133.Google Scholar