Stimulation of Cl- secretion by AlF4- and vanadate in T84 cells.
10.3346/jkms.1994.9.6.497
- Author:
Tae Ho HWANG
1
;
Jin Sup JUNG
;
Hae Rahn BAE
;
Il YUN
;
Sang Ho LEE
Author Information
1. Department of Oral Biotechnology, College of Dentistry, Pusan National University, Korea.
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords:
Cl- secretion;
AIF4-;
Vanadate;
T84 cells
- MeSH:
Aluminum/*pharmacology;
Amphotericin B/pharmacology;
Carbachol/pharmacology;
Cell Polarity;
Cells, Cultured/drug effects;
Chloride Channels/drug effects/*physiology;
Chlorides/*physiology;
Colon;
Electrophysiology;
Fluorine/*pharmacology;
Forskolin/pharmacology;
GTP-Binding Proteins/physiology;
Human;
Pertussis Toxin;
Potassium/pharmacology;
Potassium Channels/drug effects/physiology;
Second Messenger Systems;
Signal Transduction;
Support, Non-U.S. Gov't;
Vanadates/*pharmacology;
Virulence Factors, Bordetella/pharmacology
- From:Journal of Korean Medical Science
1994;9(6):497-504
- CountryRepublic of Korea
- Language:English
-
Abstract:
We investigated the mechanism of Cl- secretion by fluoroaluminate(AlF4-) and sodium orthovanadate(vanadate) using the human colonic T84 cell line. T84 cell monolayers grown on collagen-coated filters were mounted in Ussing chambers to measure short circuit current(ISC). Serosal addition of AlF4- or vanadate to T84 monolayers produced a sustained increase in ISC. Removal of Ca2+ from the serosal bathing solution partially inhibited AlF4-(-)and vanadate-induced ISC, and readministration of Ca2+ restored AlF4-(-)and vanadate-induced ISC. Carbachol application in the presence of forskolin, AlF4- or vanadate induced a synergistic increase of ISC. Forskolin and vanadate significantly increased cellular cAMP level, while carbachol and AlF4- did not. Carbachol, AlF4- and vanadate significantly increased [Ca2+]i. After Na+ in mucosal bathing solution was replaced with K+, and the mucosal membrane of T84 cell was permeabilized with amphotericin B, AlF4-, vanadate, and carbachol increased K+ conductance, but forskolin did not. After sodium chloride in serosal bathing solution was replaced with sodium gluconate and the serosal membrane was permeabilized with nystatin, forskolin, AlF4-, and vanadate increased Cl- conductance, but carbachol did not. AlF4-(-)induced ISC was remarkably inhibited by the pretreatment of pertussis toxin(2 micrograms/ml) for 2 hours. These results indicate that AlF4- and vanadate can increase Cl- secretion via simultaneous stimulation of Cl- channel and K+ channel in T84 cells. However, the AlF4- action is mostly attributed to stimulation of pertussis toxin-sensitive G-proteins, whereas the vanadate action mostly results from G protein-independent mechanisms.
