Triggered activity in atrial myocytes is influenced by Na⁺/Ca²⁺ exchanger activity in genetically altered mice.

ABSTRACT:

Aims

In atrial fibrillation, increased function of the Na⁺/Ca²⁺-exchanger (NCX) is one among several electrical remodeling mechanisms.

Methods/results

Using the patch-clamp- and Ca²⁺ imaging-methods, we investigated atrial myocytes from NCX-homozygous-overexpressor (OE)- and heterozygous-knockout (KO)-mice and their corresponding wildtypes (WT_OE; WT_KO). NCX mediated Ca²⁺ extrusion capacity was reduced in KO and increased in OE. There was no evidence for structural or molecular remodeling. During a proarrhythmic pacing-protocol, the number of low amplitude delayed afterdepolarizations (DADs) was unaltered in OE vs. WT_OE and KO vs. WT_KO. However, DADs triggered full spontaneous action poten

SUBMITTER: Bogeholz N 

PROVIDER: S-EPMC5784756 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature