Fig. 1.

Silent information regulator of transcription 1 (SIRT1) is required for ischemic preconditioning (IPC). A: wild-type (WT) and SIRT-deficient (SIRT1^+/−) hearts were perfused in Langendorff mode and subjected to ischemia-reperfusion (I/R) injury with or without IPC. The rate-pressure product (RPP; equal to left ventricular developed pressure × heart rate) indicated functional recovery during I/R injury and was monitored thought the whole experiment. Data are meanss ± SE; n ≥ 5. *P < 0.05 vs. I/R alone (by ANOVA). B: infarct size (IS) was quantified by 2,3,5-tetraphenyltetrazolium chloride (TTC) staining. AAR, area at risk. The top graph shows individual data points for each condition on the left, with means ± SE on the right. *P < 0.05 vs. I/R alone (by ANOVA). The bottom images show representative TTC-stained hearts from each experimental group.