Effect of deferoxamine on autophagy in hippocampal neurons after exploratory laparotomy in aged rats

Objective To investigate the effect of deferoxamine on autophagy in hippocampal neurons after exploratory laparotomy in aged rats. Methods Forty-four healthy male Sprague-Dawley rats, aged 18 months, weighing 500-600 g, were randomly divided into 2 groups(n=22 each)using a random number table: operation group(group O)and deferoxamine group(group D). In group D, deferoxamine 50 mg/kg was injected intraperitoneally once a day for 14 consecutive days, while the equal volume of normal saline was given instead in group O. Exploratory laparotomy was performed at 2 h after administration on 7th day.Learning and memory function was assessed using Morris water maze test which was performed before operation and at 1, 3, and 7 days after operation.The escape latency and swimming distance were recorded.The rats were sacrificed, and the hippocampi were removed for determination of the expression of Beclin-1, ferritin H and ferritin L by Western blot. Results Compared with the value before operation, the escape latency and swimming distance were significantly prolonged at each time point after operation in group O(P 0.05). Compared with group O, the escape latency and swimming distance were significantly shortened, the expression of Beclin-1 was up-regulated, and the expression of ferritin H and ferritin L was down-regulated at each time point after operation in group D(P<0.05). Conclusion Deferoxamine reduces postoperative cognitive dysfunction probably through inducing autophagy in hippocampal neurons, degrading ferritin and inhibiting iron overload in the brains of aged rats. Key words: Deferoxamine; Cognitive disorders; Hippocampus; Autophagy