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Maxi K[sup +] channel mediates regulatory volume decrease response in a human bronchial epithelial cell line.
- Source :
-
American Journal of Physiology: Cell Physiology . Dec2002, Vol. 283 Issue 6, pC1705. 10p. 2 Diagrams, 37 Graphs. - Publication Year :
- 2002
-
Abstract
- The cell regulatory volume decrease (RVD) response triggered by hypotonic solutions is mainly achieved by the coordinated activity of Cl[sup -] and K[sup +] channels. We now describe the molecular nature of the K[sup +] channels involved in the RVD response of the human bronchial epithelial (HBE) cell line 16HBE14o-. These cells, under isotonic conditions, present a K[sup +] current consistent with the activity of maxi K[sup +] channels, confirmed by RT-PCR and Western blot. Single-channel and whole cell maxi K[sup +] currents were readily and reversibly activated following the exposure of HBE cells to a 28% hypotonic solution. Both maxi K[sup +] current activation and RVD response showed calcium dependency, inhibition by TEA, Ba[sup 2+], iberiotoxin, and the cationic channel blocker Gd[sup 3+] but were insensitive to clofilium, clotrimazole, and apamin. The presence of the recently cloned swelling-activated, Gd[sup 3+]-sensitive cation channels (TRPV4, also known as OTRPC4, TRP12, or VR-OAC) was detected by RT-PCR in HBE cells. This channel, TRPV4, which senses changes in volume, might provide the pathway for Ca[sup 2+] influx under hypotonic solutions and, consequently, for the activation of maxi K[sup +] channels. [ABSTRACT FROM AUTHOR]
- Subjects :
- *POTASSIUM channels
*CALCIUM
*CELL physiology
*BRONCHI
*EPITHELIAL cells
Subjects
Details
- Language :
- English
- ISSN :
- 03636143
- Volume :
- 283
- Issue :
- 6
- Database :
- Academic Search Index
- Journal :
- American Journal of Physiology: Cell Physiology
- Publication Type :
- Academic Journal
- Accession number :
- 9451428