Small conductance calcium-activated potassium current and the mechanism of atrial arrhythmia in mice with dysfunctional melanocyte-like cells.

ABSTRACT:

Background

The melanin synthesis enzyme dopachrome tautomerase (Dct) regulates intracellular Ca(2+) in melanocytes. Homozygous Dct knockout (Dct(-/-)) adult mice are vulnerable to atrial arrhythmias (AA).

Objective

The purpose of this study was to determine whether apamin-sensitive small conductance Ca(2+)-activated K(+) (SK) currents are upregulated in Dct(-/-) mice and contribute to AA.

Methods

Optical mapping was used to study the membrane potential of the right atrium in Langendorff perfused Dct(-/-) (n = 9) and Dct(+/-) (n = 9) mice.

Results

Apamin prolonged action potential duration (APD) by 18.8 ms (95% confidence interval [CI] 13.4-24.1 ms) in Dct(-/-) mice and by 11.5 ms (95% CI 5.4-17.6 ms) in Dct(+/-) mice at a pacing cycle length of 150 ms (P = .047

SUBMITTER: Tsai WC 

PROVIDER: S-EPMC4916027 | biostudies-literature | 2016 Jul

REPOSITORIES: biostudies-literature