Male New Zealand White male rabbits were anesthetized with 30 mg/kg pentobarbital sodium and maintained in an anesthetized state with 16 mg/kg/hour by continuous infusion of pentobarbital sodium. Fluid-filled catheters were placed in the jugular vein for drug administration and in the carotid artery for blood pressure measurements and for blood gas analysis. The heart was exposed by left thoracotomy and a suture was placed around a prominent branch of the left coronary artery. When arterial pressure, HR, and RPP had stabilized, the rabbits received a 15-second bolus of either 15.4 mg.kg of ingliforib or vehicle control, followed by constant infusion of 23.1 mg/kg/hour ingliforib or vehicle control for a total of 3.5 hours. Sixty minutes after the start of infusion, regional ischemia was produced by tightening the coronary artery snare for 30 min. The snare was released, and the heart was reperfused for an additional 120 min. At the end of either the ischemic period or reperfusion period, each rabbit was euthanized with an intravenous overdose of pentobarbital sodium (100 mg/kg). The heart was quickly excised and prepared for measurement of GP activity and glycogen content, or mounted on a Langendorff apparatus and perfused with physiological saline at 38.5°C for subsequent determination of infarct size. Baseline HR, MAP, and RPP were similar between vehicle control and ingliforib-treated groups. Ingliforib did not affect MAP or RPP; a modest reduction in HR of the ingliforib group was observed during reperfusion. Infarct size was significantly reduced by 52% in vivo while the the %AAR/LV did not differ. At the end of the 30-min period of regional ischemia, GPa and total GP activity were reduced by 65% and 40%, respectively, in the ischemic myocardium, and 41% and 33%, respectively, in the nonischemic myocardium

The heart of anesthetized Male New Zealand White rabbits was rapidly removed from the chest and mounted in a Langendorf apparatus with a snare around the prominent branch of the left coronary artery. The heart was maintained by noncirculating perfusion in a modified Krebs solution of 118.5 mM NaCl, 4.7 mM KCl, 1.2 mM MgSO4, 1.2 mM KH2PO4, 24.8 mM NaHCO3, 2.5 mM CaCl2, and 10 mM glucose at a constant pressure of 80 mmHg in a heated water-jacketed organ bath with a temperature of 38.5°C. Perfusate pH was maintained at 7.4 to 7.5 by bubbling with 95% O2-5% CO2. A latex balloon was used to maintain a systolic pressure of 80-120 mmHg (<10 mmHg diastolic pressure) in the left ventricle. After a 30 min equilibration period, a constant perfusion of ingilforib (0.1, 1, or 10 microM) was initiated and maintained for the duration of the experiment. After 30 minutes of drug perfusion, a regional ischemia was produced by tightening the snare around the branch of the coronary artery. At the end of the ischemic period, the snare was released, and the heart reperfused for an additional 120 min. Administration of ingliforib did not significantly affect HR, LVDP, or CF in the isolated hearts. Ingliforib elicited a concentration-dependent reduction in infarct size in the isolated rabbit hearts; maximum reduction (69%) achieved with 10 microM ingliforib.