Aim: The aim of this study was to investigate the effect of membrane stretch on the activity of BKCa channels and determine whether change in BKCa-channel activity induced by membrane stretch can be altered in the presence of riluzole. Methods: The effect and mechanisms of membrane stretch on the activity of large-conductance Ca2+-activated K + (BKCa) channels in human retinal pigment epithelial (RPE) cells were investigated using the patch-clamp technique. Results: In cell-attached patches, an increase in BKCa-channel activity was induced by membrane stretch, which is mainly mediated by the increase in the number of long-lived openings. With inside-out patches, application of pipette suction did not modify single-channel conductance of BKCa channels; however, it did enhance the channel activity. Membrane stretch-induced channel activity was found to be independent of the level of intracellular Ca 2+. Membrane stretch also potentiated riluzole-stimulated BK Ca-channel activity. Conclusions: BKCa channel can be stimulated by membrane stretch in human RPE cells. During an increase in tensile strength of RPE, the BKCa channel might exert a protective action against deleterious tension by promoting a hyperpolarizing outflow that forces the cell to rest.
All Science Journal Classification (ASJC) codes
- Pharmacology (medical)
- Pharmacology, Toxicology and Pharmaceutics(all)