The Protective Effect Of Remote Organ Preconditioning On Focal Cerebral Ischemia/Reperfusion Injury In Rats

Background and purpose: Ischemic preconditioning (IP) is a phenomenon whereby a brief episode of sublethal ischemia and other nonlethal stressors produce protection against a subsequent detrimental ischemic insult Initially IP was described in heart, subsequently, it has been demonstrated in brain, skeletal muscle, liver, kidney, lung and small intestine. More recently, it was also reported that an ischemic episode in one organ can augment ischemic tolerance in another organ, this cross-tolerance was termed as remote organ preconditioning. Most investigations on remote organ preconditioning are now focused on heart and kidney, the question, however, whether remote organ preconditioning can also be protective to brain is still unknown. Neurons share their genetic information with other cells, it is natural, and therefore, to postulate that the brain can acquire transient tolerance by a preceding stress as in other cells, we investigated the effects of intestine preconditioning on brain during focal cerebral ischemic/reperfusion inpreconditioning on brain during focal cerebral ischemic/reperfusion in rats.Method: Animals subject to 2 h middle cerebral artery occlusion and 24 h reperfusion using the intraluminal filament model. In the intestine ischemic preconditioning groups animals subject to 4 cycles 5-min ischemia and 5-min reperfusion of the small intestine 24, 48 and 72 h before middle cerebral artery occlusion. Neurological deficits examination was performed at 3, 12 and 24 h after middle cerebral artery occlusion. After the last examination the animals were sacrificed, the infarction volumes were determined, and the contents of lactic acid (LA), maleic dialdehyde (MDA) and the activities of stiperoxide dismutase (SOD) in the brains were also measured.Results: Pretreatment with small intestine preconditioning for 24, 48, and 72 h significantly alleviated neurological deficits and reduced the infarction volumes of the rats compared with the group without small intestine preconditioning. The contents of LA and MDA were lower, while the activities of SOD in the brain tissues were higher in each group following small intestine preconditioning than the group without small intestine preconditioning.Conclusions: Small intestine preconditioning could induce brain tolerance, and increase the antioxidant activity, which might be an important mechanism of induction of brain tolerance.