Fig. 1.

Experimental setup and protocol. a Schematic diagram of the modified Langendorff retrograde heart perfusion system. b The experimental timeline. Baseline perfusion of the mouse heart was done with Krebs-Henseleit buffer solution at 37 °C (15 min). Then, the perfusion was switched to St Thomas’ II cardioplegia (6–9 °C) for 6 min. Following cardioplegic perfusion, the heart was subjected to 90 min of ischemia, where the heart remained submerged in cardioplegia at room temperature (20–24 °C). Subsequently, the heart was reperfused with Krebs-Henseleit solution (37 °C) for 30 min and recovery of heart function was recorded