In:
American Journal of Physiology-Heart and Circulatory Physiology, American Physiological Society, Vol. 274, No. 5 ( 1998-05-01), p. H1643-H1654
Abstract:
Several aspects of the effect of the KPQ deletion mutation on Na + channel gating remain unresolved. We have analyzed the kinetics of the early and late currents by recording whole cell and single-channel currents in a human embryonic kidney (HEK) cell line (HEK293) expressing wild-type and KPQ deletion mutation in cardiac Na + channels. The rate of inactivation increased three- to fivefold between −40 and −80 mV in the mutant channel. The rate of recovery from inactivation was increased twofold. Two modes of gating accounted for the late current: 1) isolated brief openings with open times that were weakly voltage dependent and the same as the initial transient and 2) bursts of opening with highly voltage-dependent prolonged open times. Latency to first opening was accelerated, suggesting an acceleration of the rate of activation. The ΔKPQ mutation has multiple effects on activation and inactivation. The aggregate effects may account for the increased susceptibility to arrhythmias.
Type of Medium:
Online Resource
ISSN:
0363-6135
,
1522-1539
DOI:
10.1152/ajpheart.1998.274.5.H1643
Language:
English
Publisher:
American Physiological Society
Publication Date:
1998
detail.hit.zdb_id:
1477308-9
SSG:
12
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