A model of cerebral ischemia induction in neonatal rabbits

Perinatal cerebral ischemia is a major cause of brain damage in the human newborn. Animal models of the brain ischemia provided important roles for extension of the pathophysiological knowledge and evaluating of the efficacy of therapeutic interventions. The purpose of the present study was to introduce a cerebral ischemia model of rabbit neonates which provides useful clues for assessing the ischemic insult in human newborns. Different time occlusion of maternal uterine arteries in five groups of 10 timed pregnant rabbits (n = 2) was done to induce cerebral ischemia in their neonates. Twenty-eight neonates with ischemic time schedules including 0 (control group), 6, 8, 10 and 15 minutes were delivered, left to recover, and clinically evaluated. After decapitation, cerebral lesions were assessed pathologically. Microscopic analyses of brain sections from experimental groups showed degrees of swelling and deformity in neurons of hippocampus which increased by increasing of time of uterine artery occlusion (p <0.01). Ischemic changes were apparent after 8 minutes of hypoxia. Sever necrosis and massive neuronal loss were observed at 10 minutes of hypoxia and over. Occlusion of maternal uterine arteries in timed pregnant rabbit for 8 minutes can be used as an animal model for evaluation of brain ischemia in human investigations.