ISSN:
1432-1017
Keywords:
Red cell, K+ channel
;
Ca2+ dependence
;
single-channel current
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Physics
Notes:
Abstract Elevated levels of intracellular Ca2+ activate a K+-selective permeability in the membrane of human erythrocytes. Currents through single channels were analysed in excised inside-out membrane patches. The effects of several ions that are known to inhibit K+ fluxes are described with respect to the single-channel events. The results suggest that the blocking ions can partly move into the channels (but cannot penetrate) and interact with other ions inside the pore. The reduction of single-channel conductance by Cs+, tetraethylammonium and Ba2+ and of single-channel activity by quinine and Ba2+ is referred to different rates of access to the channel. The concentration- and voltage-dependent inhibition by ions with measurable permeability (Na+ and Rb+) can be explained by their lower permeability, with single-file movement and ionic interactions inside the pore.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00260428
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