Ischemic preconditioning reduces the severity of ischemia-reperfusion injury of peripheral nerve in rats

BACKGROUND AND AIM Allow for protection of briefly ischemic tissues against the harmful effects of subsequent prolonged ischemia is a phenomenon called as Ischemic Preconditioning (IP). IP has not been studied in ischemia-reperfusion (I/R) model of peripheral nerve before. We aimed to study the effects of acute IP on I/R injury of peripheral nerve in rats. METHOD 70 adult male rats were randomly divided into 5 groups in part 1 experimentation and 3 groups in part 2 experimentation. A rat model of severe nerve ischemia which was produced by tying iliac arteries and all identifiable anastomotic vessels with a silk suture (6-0) was used to study the effects of I/R and IP on nerve biochemistry. The suture technique used was a slip-knot technique for rapid release at time of reperfusion in the study. Cytoplasmic vacuolar degeneration was also histopathologically evaluated by light microscopic examination in sciatic nerves of rats at 7th day in part 2 study. RESULTS 3 hours of Reperfusion resulted in an increase in nerve malondialdehyde levels when compared with ischemia and non-ischemia groups (p < 0.001 and p < 0.0001 respectively). IP had significantly lower nerve MDA levels than 3 h reperfusion group (p < 0.001). The differences between ischemic, IP and non-ischemic control groups were not significant (p > 0.05). There was also a significant decrease in vacuolar degeneration of sciatic nerves in IP group than I/R group (p < 0.05). CONCLUSION IP reduces the severity of I/R injury in peripheral nerve as shown by reduced tissue MDA levels at 3rd hour of reperfusion and axonal vacuolization at 7th postischemic day.