Effect of sevoflurane preconditioning on TREK-1 channel expression in hippocampus after focal cerebral ischemia-reperfusion in rats

Abstract

Objective To investigate the effect of sevoflurane preconditioning on TREK-1 channel expression in hippocampus after focal cerebral ischemia-reperfusion (I/R)in rats and the mechanism.Methods Thirty-six male SD rats weighing 240-280 g were randomly divided into 3 groups(n=12 each):group Ⅰ sham operation (group S),group Ⅱ I/R and group Ⅲ sevoflurane preconditioning (group Sevo).Focal cerebral ischemia was produced by inserting a 4-0 nylon thread with rounded tip into right internal jugular vein.The nylon thread was the nylon thread Wag about 18-20 Innl.The right middle cerebral artery(MCA)Wag occluded for 2 h and then released for 24 h reperfusion.The Sevo group inhaled 2.4% sevoflurane for 30 min at l h before ischemia.Neurological deftcits were assessed and scored at the end of 24 h reperfusion (the higher was the score,the severer was the deficit).The cerebral infarct size was determined by TTC staining and the TREK-1 mRNA in hippocampus by RT-PCR.Results The cerebral infarct size was significantly smaller and the neurological deficit scores were significantly lower in Sevo group than in I/R group.The TREK-1 mBNA expression was significantly up-regulated in Sevo group as compared with I/R group.Conclusion Sevoflurane preconditioning Can protect the brain against I/R injury by activating TREK-1 in hippocampus. Key words: Inhalation anesthetics; Ischemic preconditioning; Infarction,middle cerebral artery; Potassium channels,tandem pore domain; Hippocampus