Linked Life Data

1415516

Source:http://linkedlifedata.com/resource/pubmed/id/1415516

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3 Pt 1
pubmed:dateCreated
1992-10-29
pubmed:abstractText
Volume-sensitive basolateral K+ channels were studied in apically amphotericin B-permeabilized HT-29/B6 monolayers in Ussing chambers with current fluctuation analysis. The basolateral K+ conductance and Lorentzian K+ channel noise were osmotically activated in presence of Cl- concentrations greater than or equal to 74 mM. Under isotonic conditions with 148 mM Cl-, a large transepithelial K+ current of 500 +/- 16.8 microA/cm2 and a spontaneous Lorentzian K+ channel noise with a corner frequency of 29.8 +/- 1.6 Hz (n = 31) were observed. Increasing extracellular osmolalities by addition of sucrose sensitively decreased the K+ current across the basolateral membrane. Half-maximal sucrose concentration was 20 +/- 6 mM for this shrinkage maneuver. The osmotically sensitive K+ pathway was similarly activated with the halide Br- and selective for K+ over Rb+ (4:1). The established K+ channel blockers lidocaine [50% inhibitory concentration (IC50) = 49.0 +/- 3.7 microM], quinidine (IC50 = 10.1 +/- 1.3 microM), and also the chloride channel blocker 5-nitro-2-(3-phenylpropylamino)benzoic acid (IC50 = 114 +/- 2.1 microM) completely inhibited basolateral K+ currents, whereas 46% of K+ current was blocked by barium (IC50 = 95.3 +/- 23.2 microM). Osmotic sensitivity of this K+ conductance made a correction for hypertonic effects of added blockers necessary, and considerable osmotic effects of blockers at commonly used doses were shown. All blockers induced dose dependently additional Lorentzian noise, indicating a direct inhibitory action on basolateral K+ channels. In this human Cl- secretory cell line, volume-sensitive K+ channels are localized only in the basolateral membrane and may modulate osmotic regulation when HT-29 cells swell.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
263
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C674-83
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Volume-sensitive basolateral K+ channels in HT-29/B6 cells: block by lidocaine, quinidine, NPPB, and Ba2+.
pubmed:affiliation
Department of Veterinary Physiology, Free University Berlin, Federal Republic of Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't