Thyroid hormone postconditioning protects hearts from ischemia/reperfusion through reinforcing mitophagy.

•THPostC concentration-dependently improved post-ischemic contractile function and reduces the cell death during I/R.•THPostC alleviates mitochondrial dysfunction of cardiomyocytes during simulated I/R.•THPostC activates I/R-induced mitophagy and suppresses mitophagy blocks protective effects of THPostC.•PINK1-Parkin pathway is responsible for THPostC-afforded cardioprotective effects.