Background chloride currents in fetal human nasopharyngeal epithelial cells / 生理学报
Acta Physiologica Sinica
;
(6): 349-354, 2005.
Article
in Chinese
| WPRIM
| ID: wpr-334164
ABSTRACT
To characterize the background current in fetal human nasopharyngeal epithelial cells and clarify its relationship with volume activated Cl(-) currents (I(Cl,vol)), whole-cell patch clamp and cell imaging techniques were employed. Under isotonic conditions, a background current [(5.9+/-2.1) pA/pF at +80 mV, n=21] was detected. The current presented a weak outward rectification and a negligible time-dependent inactivation. The current-voltage relationship showed that the reversal potential of the background current [(-0.73+/-1.7) mV, n=21] was close to the calculated equilibrium potential for Cl(-)(-0.9 mV). Application of extracellular hypertonic stimulation (440 mOsmol/L) suppressed the current by (59.6+/-7.1)% and the inhibition was reversible after returned to isotonic conditions. Bathing the cells in hypotonic solution (160 mOsmol/L) induced a volume-sensitive Cl(-) current. The Cl(-) channel blockers, tamoxifen (20 micromol/L) and 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) (100 micromol/L), inhibited the background current by (74.0+/-5.2)% (P<0.01, n=5) and (60.9+/-8.9)% (P<0.01, n=6) at +80 mV and increased basal cell volume by (107.7+/-2.9)% (P<0.01, n=25) and (104.4+/-2.4)% (P<0.01, n=19), respectively. The data indicate that Cl(-) current is an important component of the background current in fetal human nasopharyngeal epithelial cells. The background Cl(-) current is involved in volume activated Cl(-) current and basal cell volume regulation.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Pharmacology
/
Physiology
/
Tamoxifen
/
Cells, Cultured
/
Nasopharynx
/
Chloride Channels
/
Patch-Clamp Techniques
/
Cell Biology
/
Electrophysiology
/
Epithelial Cells
Limits:
Humans
Language:
Chinese
Journal:
Acta Physiologica Sinica
Year:
2005
Type:
Article
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