Effect of hyperbaric oxygen treatment on postoperative cognitive dysfunction in rats / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of hyperbaric oxygen (HBO) treatment on postoperative cognitive dysfunction (POCD) in rats.Methods Eighteen healthy male Sprague-Dawley rats,weighing 260-290 g,were anesthetized with intraperitoneal 10％ chloral hydrate 350 mg/kg.POCD was induced by injecting Aβ-40 2μl into the bilateral hippocampi by using a brain stereotaxic apparatus.The rats were randomly divided into 3 groups (n =6 each) using a random number tablenormal sahne group (group NS),POCD group,and HBO treatment group(groupHBO).0.9％ normal saline 2 μl was injected into hippocampus in group NS.In group POCD,Aβ0 2 μl was injected into hippocampus.In group HBO,Aβ 2μl was injected into hippocampus,and then the rats received hyperbaric oxygen treatment lasting for 60 min once a day within 1-5 days after operation.Morris water maze test was performed on 7,14 and 21 days after operation in each group and the swimming distance and speed and escape latency were recorded.The animals were sacrificed after the end of test,the hippocampi were then removed to detect the activation of astrocytes (by immuno-histochemistry) and content of tumor necrosis factor-α (TNF-α) (by ELISA).Resets There were no significant differences in the parameters of behavior in Morris water maze test on 7 and 14 days after operation between the three groups.Compared with group NS,the swimming distance and escape latency were significantly prolonged,and the activation of astrocytes and TNF-α content were increased on 21 days after operation in group POCD,and the swimming distance and escape latency were significantly prolonged,the activation of astrocytes was increased,and no significant change was found in TNF-α content on 21 days after operation in group HBO.Compared with group POCD,the swimming distance and escape latency were significantly shortened,and the activation of astrocytes and TNF-α content were decreased in group HBO.There was no significant difference in the swimming speed at each time point among the three groups.Conclusion HBO treatment can alleviate POCD in rats,and the mechanism is related to inhibition of activation of astrocytes and inflammatory responses in hippocampi by HBO.