ISSN:
1420-9071
Keywords:
Maxi-chloride channel
;
HT-29
;
intestinal epithelium
;
electrolyte transport
;
Ca2+-ionophore
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract In excised inside-out membrane patches of the human colon carcinoma HT-29cl.19A cells a large conductance (373±10 pS) chloride channel was found. Channel activity could only be observed after excision of patches from cells incubated with calcium ionophore. The channel was never observed in cell-attached patches. The channel was strongly voltage dependent, being open only between +30 and −30 mV clamp potentials. The selectivity sequence among anions, deduced from reversal potentials, was I〉Br〉Cl〉F〉gluconate. The PNa/PCl was 0.09. Although a similar type of channel, has been described earlier, this is the first report stating its appearance in patches of intestinal epithelial cells requiring the combined action of Ca2+ ionophore and excision, suggesting its control by an intracellular compound.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01923409
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