Abstract: Objective To study the protective effects of noninvasive delayed limb ischemic preconditioning against cerebral ischemia-reperfusion oxidative injury in rats. Method Wistar rats were divided randomly into sham operation(sham), ischemia-reperfusion(I/R), early cerebral ischemic preconditioning and ischemia-reperfusion(ECIP+I/R), and noninvasive delayed limb ischemic preconditioning and ischemia-reperfusion(NDLIP+I/R) groups. Rats in NDLIP+I/R group were subjected to three cycles of five minutes ischemia/five minutes reperfusion on the left hind limb, once a day for three consecutive days. On the forth day, all rats were subjected to cerebral ischemia/reperfusion injury. Rats　in ECIP+I/R group were preconditioned　before ischemia. Neurological score and cerebral infarct size(IS) were examined after ischemia 1h and reperfusion 24h. Activity of superoxide dismutase (SOD) and concentration of malondialdehyde (MDA) were measured. Results Compared with I/R group, ECIP+I/R and NDLIP+I/R could reduce neurological score significantly after ischemia 1h and reperfusion 24h(P<0.01). Compared with I/R group, ECIP+I/R and NDLIP+I/R could reduce IS and concentration of MDA, increase total SOD（T-SOD）and Mn-SOD activity in hippocamppus and cortex(P<0.01). Among all these oxidative and antioxidative substancese, there was no significance between ECIP+I/R and NDLIP+I/R. Conclusion The protective effects of NDLIP against cerebral ischemia-reperfusion injury are similar to those of ECIP, the protective effects are associated with the increase in antioxidative ability of brain.

Key words: Limb, Remote ischemic preconditioning, Cerebral ischemia-reperfusion injury, Superoxide dismutase, Malondialdehyde