Protective Effects Of Hyperbaric Oxygen Pretreatment And Post-treatment On Cognitive Impairment Induced By Hypobaric Hypoxia In Rats

Objective:This experiment intends to study whether hyperbaric oxygen pretreatment and post-treatment have a protective effect on the cognitive dysfunction of rats caused by low pressure and hypoxia environment,and to study the possible points of Nrf2,HO-1 proteins in the progress of preventing their effects.Methods:Pretreatment: Forty males(180-22 g body weight)were divided four groups and the first group was treated separately,with no vacancies and no treatment;The second group was the hyperbaric oxygen control group,and only HBOP was administered once a day,for a total of 5 times;the third group is a hypobaric hypoxic group of 10;Group 4 requires hyperbaric oxygen and hypobaric oxygen therapy.The high-pressure oxygen pretreatment is the same as the second group.After the treatment ends,it will receive two consecutive days of low-pressure and hypoxic treatment);Postreatment:Forty males(180-22 g body weight)were divided four groups and the first group was treated separately,with no vacancies and no treatment;The second group was the hyperbaric oxygen control group,and only HBOP was administered once a day,for a total of 5 times;the third group is a hypobaric hypoxic group of 10(receiving 2consecutive Days of low-pressure and hypoxic treatment);the fourth group is hyperbaric oxygen post-treatment + low-pressure hypoxic group of 10(first receive low-pressure hypoxic treatment for two consecutive days,and then receive high-pressure treatment once a day for five consecutive days after the treatment);The hyperbaric oxygen conditions of the pretreatment group and the post-treatment group were 2.5ATA,the oxygen concentration should exceed 80%,and the CO2 concentration <0.05%;the hypobaric oxygen conditions of the pretreatment group and the post-treatment group were 350 mm Hg,6%-7% O2.Morris water maze and Y maze were used to evaluate the cognitive function of rats on the 8th day after hypoxia treatment.After low-pressure oxygen treatment,proinflammatory factors in serum of experimental animals should be determined regularly and completed at different time points to determine the contents of IL-6,IL-1β,TNF-α,and the protein expression of Nrf2 and HO-1 in hippocampal tissues of rats in each group.Results:1、The rats in the hyperbaric oxygen pretreatment + hypobaric hypoxia treatment group and the hyperbaric oxygen posttreatment + hypobaric hypoxia treatment group were in the Y maze.In the experiment,the alternating score rate was significantly higher than that of the rats in the low-pressure and hypoxic treatment group.2、ELISA results showed TNF Levelsα,IL-1β,IL-6 were significantly lower at different time points after treatment of hypovascular hypoxia,the hyperbaric oxygen pretreatment group and the post-treatment group of the hypovascular therapy group.3、The expression of Nrf2 and HO-1 proteins in the hippocampus of rats in the hyperoxia group and after treatment was significantly higher than in the oxygen and oxygen treatment groups.4、Compared with the blank control group,there was no significant difference in CI in the HBOP group alone.Conclusion:Acute low-pressure and hypoxic environment may cause damage to rats,leading to the decline of their early cognitive function,and hyperbaric oxygen pretreatment and post-treatment can alleviate the degree of cognitive decline.To explore its mechanism,it is considered that the release of pro-inflammatory factors is reduced after hyperbaric oxygen treatment,causing moderate oxidative stress,increasing the expression of Nrf2 protein in the hippocampus,thereby producing neuroprotective effects.