Activation of chloride current and decrease of cell volume by ATP in nasopharyngeal carcinoma cells.
- Author:
Qing-Feng HE
1
;
Li-Wei WANG
;
Jian-Wen MAO
;
Xue-Rong SUN
;
Pan LI
;
Ping ZHONG
;
Si-Huai NIE
;
Tim JACOB
;
Li-Xin CHEN
Author Information
1. Laboratory of Cell Biology, Guangdong Medical College, Zhanjiang 524023, China.
- Publication Type:Journal Article
- MeSH:
Adenosine Triphosphate;
physiology;
Cell Size;
drug effects;
Chloride Channels;
antagonists & inhibitors;
metabolism;
physiology;
Humans;
Nasopharyngeal Neoplasms;
metabolism;
pathology;
Nitrobenzoates;
pharmacology;
Patch-Clamp Techniques;
Tumor Cells, Cultured
- From:
Acta Physiologica Sinica
2004;56(6):691-696
- CountryChina
- Language:English
-
Abstract:
Whole-cell patch clamp and cell volume measurement techniques were used to investigate the ATP-activated chloride current and the ATP effect on cell volume in nasopharyngeal carcinoma cells. Extracellular application of ATP in micromolar concentrations activated a current with the properties of modest outward rectification and negligible time-dependent inactivation in a dose-dependent manner. The current reversed at a potential [(-0.05+/-0.03) mV] close to the Cl- equilibrium potential (-0.9 mV). Substitution of Cl- with gluconate in the extracellular solution decreased the ATP-activated current and shifted the reversal potential positively. NPPB, one of the chloride channel blockers, inhibited the current by (81.03+/-9.36)%. The current was also depressed by the P2Y purinoceptor antagonist, reactive blue 2, by (67.39+/-5.06)%. ATP (50 micromol/L) decreased the cell volume under the isotonic condition. Depletion of extracellular and intracellular Cl- abolished the ATP effect on cell volume. The results suggest that extracellular ATP of micromolar scales can induce a chloride current associated with cell volume regulation by activation of chloride channel through binding to purinoceptor P2Y.
