Fig 5. Irisin administration enhances cardiovascular function, while knockdown of irisin by siRNA attenuated cardiac physiology in zebrafish.

Exogenous irisin (0.1 ng/g, 1 ng/g and 10 ng/g B.W) increased diastole volume in zebrafish (A). siRNA knockdown of irisin (10 ng/g B.W) significantly decreased diastolic volume, systolic volume, stroke volume, heart rate and cardiac output in zebrafish (A-E). Exogenous irisin (0.1 ng/g and 1 ng/g) improved heart rate and cardiac output (D, E) in zebrafish. No significant effects on cardiovascular functions were observed upon injection of irisin scrambled siRNA, when compared to control group (A-E). Asterisks denote significant differences between control (saline group) and irisin, siRNA injected groups (* p<0.05, n = 6 fish/group). Data are represented as mean + SEM. One-way ANOVA (non-parametric) followed by Tukey’s multiple comparison test were used for statistical analysis.