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.
|Number of pages||4|
|Journal||Biochimica et Biophysica Acta|
|Publication status||Published - 10 Jun 1992|
- 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid
- 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid
- Chloride Channels
- Culture Media
- Intestine, Large
- Membrane Potentials
- Membrane Proteins
- Osmolar Concentration
- Tumor Cells, Cultured
McEwan, G. T., Brown, C. D., Hirst, B. H., & Simmons, N. L. (1992). Hypo-osmolar stimulation of transepithelial Cl- secretion in cultured human T84 intestinal epithelial layers. Biochimica et Biophysica Acta, 1135(2), 180-3.