ISSN:
1432-136X
Keywords:
Epithelium
;
Patch clamp
;
Cell-attached mode
;
NPPB
;
Cl- secretion
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Freshly isolated epithelial cells from hen colon were investigated using the patch-clamp technique. The aim of this investigation was to characterise the cellular conducting site for Cl- secretion. In cell-attached mode two types of Cl--channels were found. Both showed distinct outward rectification. The channel types differed in single channel conductances and the marked voltage dependence of the open probabilities. A low conductance Cl--channel was observed with a mean conductance at negative holding potentials of g-=9 pS, and of g+=34 pS at positive potentials. This channel was predominantly open at negative potentials, corresponding to cell hyperpolarization. The second channel type observed had conductances of g-=35 pS and g+=77 pS, and showed increasing open probabilities with increasing holding potentials (cell depolarisation). Both channel types were blockable by the Cl--channel blocker NPPB. These data in combination with previously published transepithelial transport data on hen colon indicate that these channels are the Cl- secretory sites in colon epithelium.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00260790
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