Endothelial SKCa and IKCa Channels Regulate Brain Parenchymal Arteriolar Diameter and Cortical Cerebral Blood Flow
Open Access
- 22 December 2010
- journal article
- Published by SAGE Publications in Journal of Cerebral Blood Flow & Metabolism
- Vol. 31 (5), 1175-1186
- https://doi.org/10.1038/jcbfm.2010.214
Abstract
Calcium-sensitive potassium (KCa) channels have been shown to modulate the diameter of cerebral pial arteries; however, little is known regarding their roles in controlling cerebral parenchymal arterioles (PAs). We explored the function and cellular distribution of small-conductance (SKCa) and intermediate-conductance (IKCa) KCa channels and large-conductance KCa (BKCa) channels in endothelial cells (ECs) and smooth muscle cells (SMCs) of PAs. Both SKCa and IKCa channels conducted the outward current in isolated PA ECs (current densities, ~20 pA/pF and ~28 pA/pF at + 40 mV, respectively), but these currents were not detected in PA SMCs. In contrast, BKCa currents were prominent in PA SMCs (~ 154pA/pF), but were undetectable in PA ECs. Pressurized PAs constricted to inhibition of SKCa (~ 16%) and IKCa (~ 16%) channels, but were only modestly affected by inhibition of BKCa channels (~ 5%). Blockade of SKCa and IKCa channels decreased resting cortical cerebral blood flow (CBF) by ~ 15%. NS309 (6,7-dichloro-1...Keywords
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