Figure 7: TNFα and p38 inhibition prevents arrhythmogenic atrial remodelling.

(a) Representative atrial arrhythmia induction in untreated, etanercept (Etn) treated, TNFα knockout (−/−) and p38 inhibitor SB203580 treated mice swimming exercised for 6 weeks. (b) Representative picrosirius red-stained atrial sections showing prevention of fibrosis (red) in exercised etanercept treated, exercised TNFα−/− and exercised SB203580 treated mice compared with untreated exercised mice. (c) Percentage of mice showing sustained AF episodes. Sustained episodes of AF were not induced in etanercepttreated,TNFα−/− or SB203580-treated mice with exercise. (d) Summary data showing percent fibrosis in exercised etanercept treated, exercised TNFα−/− and SB203580 treated mice. The n value shown on bar graphs and present number of mice used. Data presented as mean±s.e.m. χ²-test *P<0.05 when exercised untreated is compared with exercised+Etn, exercised TNFα−/− or exercised SB203580 treated mice. **P<0.05 when exercised untreated is compared with exercised+Etn, exercised TNFα−/−, or exercised SB203580 treated mice using one-way ANOVA with Dunnett’smultiple comparison test. Scale bar, 100 μm.