Effect of ischemic postconditioning on focal cerebral ischemia reperfusion injury in rats

Aim To investigate whether ischemic postconditioning could induce ischemic tolerance to focal cerebral reperfusion injury and comparison with ischemic preconditioning. Methods A reversible middle cerebral artery occlusion (MCAO)was used in this study. Fifty male Sprague-dawley rats were randomized into five groups(n=10): sham-operated group,MCAO group,preconditioning group, postconditioning group and nimodipin group . The neurological function was scored and the infarct volume was measured after operation. The grouping,experimental methods and procedures of another fifty rats were as above except that ipsilateral brain of infarction was dissected and made into homogenate,then the contents of MDA,SOD,GSH and LA were quantitatively measured. Results The postconditioning and preconditioning improved the neurological function,reduced the cerebral infarction volumes and cerebral swelling significantly compared with those of the MCAO group. Contents of LA and MDA were lower, while the activity of SOD in the brain tissues were higher in preconditioning group and postconditioning group than those of the MCAO group. Conclusion Postconditioning could induce brain tolerance, and increase the antioxidant activity, which might be an important mechanism of induction of brain tolerance.