A new model of global postischemic reperfusion in rabbit

Abstract

An ideal model of global ischemia in rabbits has not yet been developed. The present study describes a new model of global postischemic reperfusion (GPIR) in the rabbit, characterized by lack of systemic hypotension. The experimental procedure involves reversible occlusion of the bilateral internal carotid arteries (ICA) and bilateral external carotid arteries (ECA) for 60 min combined with permanent ligation of bilateral vertebral arteries (VA). This grouping is called 6-artery occlusion (6AO). Sixty minutes after the occlusion, bilateral ICA and bilateral ECA were released for 120 min at which time the experiment was terminated. The results revealed severely depressed EEG activity; Water content of brain tissue increased to 80.33 +/- 1.20% (control 78.28 +/- 0.59%, p less than 0.01); K, Mg, and Zn decreased (p less than 0.05 or p less than 0.01), and were negatively correlated with tissue water content. Na increased (p less than 0.05) and correlated with water content of brain. No significant changes were observed in lipid peroxide (LPO) levels, but the activity of superoxide dismutase (SOD) of brain tissue decreased (p less than 0.01), and was negatively correlated with water content (r = -0.5808, p less than 0.05). These results were compared with those obtained with the model of 4-artery (bilateral common carotid arteries (CCA) and VA) occlusion (4AO) and suggested that the brain damage be more severe with 6AO than with 4AO.