The Melatonin Receptor Agonist Ramelteon Induces Cardioprotection that Requires MT2 Receptor Activation and Release of Reactive Oxygen Species

Figures

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  Fig. 1. a, b Experimental protocol. Con, control; Ram, ramelteon; 4P-PDOT, 4-phenyl-2-propionamidotetralin; MPG, N-2-mercaptopropionylglycine; CsA, cyclosporine A

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  Fig. 2. Infarct size measurement. a Histogram shows the infarct size of controls, ramelteon, and 4P-PDOT—with and without ramelteon. b Histogram shows the infarct size of controls, ramelteon, MPG, and CsA administered at two different time points. Data are presented as means ± SD, *P < 0.05 vs. Con, #P < 0.05 vs. Ram, §P < 0.05 vs. MPG+Ram. Con, control; Ram, ramelteon; 4P-PDOT, 4-phenyl-2-propionamidotetralin; MPG, N-2-mercaptopropionylglycine; CsA, cyclosporine A

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  Fig. 3. Possible signaling cascade of ramelteon-induced cardioprotection against myocardial ischemia-reperfusion injury in rats. MT, melatonin receptor; mKCa-channel, mitochondrial large-conductance Ca2+-sensitive potassium (mKCa) channel; Paxilline, mKCa-channel inhibitor; ROS, radical oxygen species; MPG, N-2-mercaptopropionylglycine, ROS scavenger; mPTP, mitochondrial permeability transition pore; Cyclosporine A, mPTP inhibitor