Abstract
Patch-clamp recordings from rabbit corneal epithelial cells have identified a large-conductance (167 pS in symmetrical 150 mM KCl) K channel that is the major contributor to the whole cell current (J. L. Rae and G. Farrugia. J. Membr. Biol. 129: 81-87, 1992). We report here on the regulation of this channel by changes in cellular osmolality and/or volume. Exchanging the bath solution with a hyposmotic (225 or 150 mosM) solution resulted in cellular swelling and selective activation of the K current (126 ± 86 and 273 ± 184% increase, respectively). Hyperosmotic solution changes (380 mosM) resulted in cell shrinkage and deactivation of the K current (44.2 ± 21% decrease). Similar increases in the cell volume and whole cell current were observed on increasing (in perforated patch experiments) the chloride ion concentration (50 mM) in the pipette intracellular solution (127 ± 63% increase). These changes were accompanied by marked shifts in the resting membrane voltage. We conclude that the K channels in these cells can respond to alteration in cellular osmolality or volume, resulting in changes in the whole cell current and resting voltage.
Original language | English (US) |
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Pages (from-to) | C1238-C1245 |
Journal | American Journal of Physiology - Cell Physiology |
Volume | 264 |
Issue number | 5 33-5 |
DOIs | |
State | Published - 1993 |
Keywords
- channels
- corneal epithelium
- osmolar changes
- patch clamp
- volume regulation
ASJC Scopus subject areas
- Physiology
- Cell Biology