Figure 9.

Variations in conduction properties through the isolated sinoatrial node of Scn5a+/− hearts with age. A: electrograms and activation mapping in young WT (a) and young Scn5a+/− (b) as well as old WT (c) and old Scn5a+/− atria (d). B and C: sinoatrial node (SAN) cycle lengths (B) and sinoatrial conduction times in the four experimental groups (C). D–F: fibrosis-regulating, TGF-β1, vimentin, and Nav1.5 gene expression and interacting effects of ageing and genotype. D: mRNA abundance assessed by real-time polymerase chain reaction. E: correlations between gene expression of TGF-β1 and Nav1.5 (a), vimentin and Nav1.5 (b), and vimentin and TGF-β1 (c). F: TGF-β1 gene expression initiated by Nav1.5 inhibition with Nav1.5 antibody. TGF-β1 gene expression was increased by Nav1.5 antibody treatment at the transcriptional (a) and protein levels (b) in both human neonatal myocytes and fibroblasts. [From Hao et al. (408).]