Cooper, G., Fowler, M. and Hunter, M. (2001) Membrane cross-talk in the early distal tubule segment of frog kidney: role of calcium stores and chloride. Pflügers Archiv - European Journal of Physiology, 442(2), pp. 243-247. (doi: 10.1007/s004240100518)
Full text not currently available from Enlighten.
Abstract
The activities of transport mechanisms in epithelial cells are generally coordinated in order to minimise disturbances in cellular ion content and volume. Furosemide, a potent inhibitor of transport in the renal diluting segment, up-regulates apical K+ channel activity following the release of calcium from intracellular stores. The signal pathway between furosemide application and this calcium release is not known. Single early distal tubule segments from frog kidney were permeabilised with saponin in order to monitor calcium levels within cytoplasmic stores using the calcium-sensitive dye, mag-fura. The uptake (or release) of calcium to (or from) stores was initiated by adding agents to the bath solution, which is in direct contact with the intracellular organelles. ATP promoted calcium uptake into stores, whereas ATP removal led to a slower, spontaneous calcium release. Following loading, calcium stores could be rapidly depleted by inositol 1,4,5-trisphosphate (IP3), but not ryanodine. Calcium release was evident upon lowering the "intracellular" chloride concentration from 12 to 4 mM, equivalent to the fall in chloride induced by furosemide in intact cells. These results suggest that intracellular chloride may function as a second messenger, mediating cross-talk between the apical membrane and intracellular calcium stores.
| Item Type: | Articles |
|---|---|
| Status: | Published |
| Refereed: | Yes |
| Glasgow Author(s) Enlighten ID: | Fowler, Dr Mark |
| Authors: | Cooper, G., Fowler, M., and Hunter, M. |
| College/School: | College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing > Clinical Specialities |
| Journal Name: | Pflügers Archiv - European Journal of Physiology |
| Publisher: | Springer Verlag |
| ISSN: | 0031-6768 |
| ISSN (Online): | 1432-2013 |
University Staff: Request a correction | Enlighten Editors: Update this record
Deposit and Record Details
Deposit and Record Details