Extracellular sodium and potassium levels modulate cardiac conduction in mice heterozygous null for the Connexin43 gene.

ABSTRACT:

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Several studies have disagreed on measurements of cardiac conduction velocity (CV) in mice with a heterozygous knockout of the connexin gene Gja1--a mutation that reduces the gap junction (GJ) protein, Connexin43 (Cx43), by 50 %. We noted that perfusate ionic composition varied between studies and hypothesized that extracellular ionic concentration modulates CV dependence on GJs. CV was measured by optically mapping wild-type (WT) and heterozygous null (HZ) hearts serially perfused with solutions previously associated with no change (Solution 1) or CV slowing (Solution 2). In WT hearts, CV was similar for Solutions 1 and 2. However, consistent with the hypothesis, Solution 2 in HZ hearts slowed transverse CV (CVT) relative to Solution 1. Previously, we showed CV slowing

SUBMITTER: George SA 

PROVIDER: S-EPMC5131712 | biostudies-literature | 2015 Nov

REPOSITORIES: biostudies-literature