Pre-treatment of a single high-dose of atorvastatin provided cardioprotection in different ischaemia/reperfusion models via activating mitochondrial KATP channel.

A number of clinical trials have shown that a high loading dose of atorvastatin (Ator) within 24h before percutaneous coronary intervention (PCI) exerts protective effects on the cardiovascular system. However, the potential mechanisms regarding this rapid benefit of Ator remain elusive. Our study introduced three different ischaemia/reperfusion (I/R) models: I/R in vivo, I/R in vitro and oxygen-glucose deprivation/recovery (OGD/R) in primary neonatal rat cardiac myocytes to observe the protective effect of a single loading dose of Ator pre-treatment and further to explore the potential mechanisms of this protective effect with confocal laser scanning microscopy, flow cytometry, biochemical and morphology methods. We found that the pre-treatment of high-dose Ator decreased the cardiac injury and maintained the integrity of mitochondria in all three of the I/R models, which was similar to ischaemic pre-conditioning (IPC). We used the mitochondrial K(ATP) channels (mitoKATP channels) inhibitor 5-hydroxydecanoate (5-HD) and the mitochondrial permeability transition pore (mPTP) opener lonidamine (LND) to analyse the underlying mechanisms. The results showed that the pre-treatment of Ator significantly decreased I/R-induced injury, and maintained the functional integrity of mitochondria through alleviating Ca(2+) overload, reactive oxygen species burst, inhibiting the opening of mPTP and preventing mitochondrial membrane potential (ΔΨm) depolarisation. The present results demonstrated that a single dose of Ator might protect the myocardium from I/R-induced injury by inhibiting the mPTP opening through activating the mitoKATP channels. This result may contribute toward the development of novel strategies for clinical cardioprotection against I/R injury.