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

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.