Effect of isoflurane preconditioning on autophagy during focal cerebral ischemia-reperfusion injury in rats / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of isoflurane preconditioning on autophagy during focal cerebral ischemia-reperfusion (I/R) injury in rats.Methods Thirty-six healthy male Sprague-Dawley rats,weighing 250-280 g,aged 7-8 weeks,were divided into 3 groups (n =12 each) using a random number table:sham operation group (group S),cerebral I/R group (group I/R) and isoflurane preconditioning group (group IP).Focal cerebral I/R was induced by 2 h middle cerebral artery occlusion followed by 24 reperfusion.Group IP inhaled 1.5％ isoflurane for 1 h per day for 5 consecutive days,the other two groups only inhaled 30％ oxygen,and focal cerebral I/R was induced at 24 h after the last inhalation.At 24 h of reperfusion,neurologic deficit was assessed and scored,the rats were then sacrificed,and brains were removed for determination of cerebral infarct size (using triphenyl tetrazolium chloride staining) and expression of microtubule-associated protein 1 light chain 3-Ⅱ (LC3-Ⅱ) and Beclin-1 (by Western blot).Results Compared with group S,the neurologic deficit scores and cerebral infarct size were significantly increased,and the expression of hippocampal LC3-Ⅱ and Beclin-1 was significantly up-regulated in I/R and IP groups (P＜0.05).Compared with group I/R,the neurologic deficit scores and cerebral infarct size were significantly decreased,and the expression of hippocampal LC3-Ⅱ and Beclin-1 was significantly upregulated in group IP (P ＜ 0.05).Conclusion The mechanism by which isoflurane preconditioning ameliorates focal cerebral I/R injury is related to enhancement of autophagy in the rats.