and the percentage change in cell viability was calculated thirty six male sprague dawley rats 270 330 g charles river labs raleigh va were used in this study anesthesia was induced by 5 halothane and maintained at 2 halothane delivered in oxygen body temperature was maintained normothermic 37 u00b1 1 u00b0 c throughout all surgical procedures by means of a homeothermic heating system harvard apparatus south natick mass food and water were provided ad libitum before and after surgery and the animals were individually housed under a 12 h light dark cycle rats were anesthetized and prepared for temporary focal ischemia using the filament method of middle cerebral artery occlusion mcao and reperfusion briefly the right external carotid artery was isolated and its branches were coagulated a 3 0 uncoated monofilament nylon suture with a rounded tip was introduced into the internal carotid artery via the external carotid artery and advanced approximately 22 mm from the carotid bifurcation until a slight resistance was observed thus occluding the origin of the mca the endovascular suture remained in place for 2 h and then was retracted to allow reperfusion of blood to the mca after mcao surgery animals were placed in recovery cages with ambient temperature maintained at 22 u00b0 c during the 2 h ischemia period and the initial 6 h post ischemia period 75 w warming lamps were also positioned directly over the top of each cage to maintain body temperature normothermic throughout the experiment the rats were treated 10 minutes prior to mcao with 1 mg kg pan 811 via iv injection pan 811 was prepared as a stock solution in 70 peg300 30 etoh this stock was diluted 5 fold in sterile.