Figure 2.

PKA signalling in myocardial ischaemia/reperfusion injury. Both ischaemia and reperfusion induce PKA activation, which can contribute to oxidative stress and Ca²⁺ overload, leading to cardiac cell death and myocardial damage. However, cAMP-induced activation of Epac, eNOS, proteasome, and HSP20 appear to be cardioprotective. CcO, cytochrome c oxidase; ECs, endothelial cells; eNOS, endothelial nitric oxide synthase; Epac, exchange protein directly activated by cAMP; HSP20, heat shock protein 20; MnSOD, manganese superoxide dismutase; ROS, reactive oxygen species. Arrows indicate activation; bar-headed lines indicate inhibition.