2.4 Langendorff- perfused isolated hearts
Guinea pigs (male; 300-350 g) were humanely killed by intraperitoneal injection with pentobarbital sodium (50 mg/kg). Hearts rapidly excised after thoracotomy were mounted onto a Langendorff perfusion system and perfused with a modified Tyrode’s solution (119 NaCl, 25 NaHCO3, 4 KCl, 1.2 KH2PO4, 1 MgCl2, 1.8 CaCl2.2H2O, and 10 D-glucose (mM) equilibrated with 5% CO2 and 95% O2) with the flow rate of 8 ml/min at 37°C. Hearts were perfused and monitored for stability for 20 mins before experimental procedures commenced.