Abstract
Intact epithelial monolayers of T84 human colonic adenocarcinoma cells were exposed from the basolateral surfaces to hypo-osmotic media; in responsive tissues this resulted in a transient stimulation of inward short-circuit current (SCC) to a peak of 12.9 +/- 1.5 (S.E., n = 10) microA/cm2 which declined to prestimulation values of SCC (2.1 microA/cm2) within 5 min. Exposure of T84 cells to hypo-osmotic media results in an increase in cytosolic [Ca2+]i, dependent on extracellular Ca2+ influx. The cell-swelling activated SCC is abolished upon medium Cl- replacement and by 100 microM bumetanide applied to the basal-surfaces, consistent with the inward SCC resulting from transepithelial Cl- secretion. 100 microM DIDS (4,4'-diisothiocyanantostilbene-2,2'-disulphonic acid) also abolished the cell-swelling activated increase in SCC; DIDS is without effect upon the VIP-stimulated SCC, suggesting distinct Cl- channels are involved in the two responses.
Original language | English |
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Pages (from-to) | 180-3 |
Number of pages | 4 |
Journal | Biochimica et Biophysica Acta |
Volume | 1135 |
Issue number | 2 |
Publication status | Published - 10 Jun 1992 |
Keywords
- 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid
- 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid
- Bumetanide
- Calcium
- Chloride Channels
- Chlorides
- Culture Media
- Cytosol
- Epithelium
- Humans
- Intestine, Large
- Membrane Potentials
- Membrane Proteins
- Osmolar Concentration
- Tumor Cells, Cultured