Effects Of Different Inhale Oxygen Time Of Hyperbaric Oxygen On Perihematomal Edema And Expression Of Aquaporin-4 And Superoxide Dismutase In Rats With Intracerebral Hemorrhage

Objective: Hyperbaric oxygen(Hyperbaric oxygen,HBO) treatment is a way to treat disease which at higher pressures than the local environment and the concentration of oxygen inhalation higher than local atmospheric oxygen. In the pressurized cabin air inhale pure oxygen by mask or other similar device(oxygen concentrations greater than 95%), or directly in the breathe the oxygen in the oxygen cabin.That is to say,patients in the air compression chamber(or oxygen tank) inhale pure oxygen to achieve the purpose of treating disease by using physical, chemical, biological and physiological effects of oxygen, that is the HBO treatment.Intracerebral hemorrhage(intracerebral hemorrhage,ICH), also known as cerebral haemorrhage, refers to the spontaneous non-traumatic intracerebral haemorrhage. Surgery has become recognized as the saving of life in patients with acute intracerebral hemorrhage treatment, but its fastly improving the before and after operation hypoxia-ischemia and brain edema still stranded.Brain edema after intracerebral hemorrhage is a series primary damage cause the secondary pathological process, brain edema, which can cause nerve injury worsened again, resulting in increased mortality and therefore reduce intracerebral edema is the key to clinical treatment of intracerebral hemorrhage. Clinical and basic studies have shown that intracerebral hemorrhage following intervention of hyperbaric oxygen treatment can reduce brain oedema, impaired neurological function can be improved but there is no wide support from clinical and basic research data. Aquaporins(aquaporins,AQPs) is a group of important membrane transport proteins that can change cell membrane permeability to watermolecules and maintain the water balance of internal and external of cell. In the CNS(central nervous system,CNS), AQP4 mainly in the star-shaped glial cells,ependymal cells and so on. Studies have found that AQP4 increasing is ralated to the increased permeability of the blood-brain barrier and brain edema formation. Foundation research shows that HBO can inhibit bleeding around AQP4 after ICH, thereby reducing the formation of brain edema after intracerebral hemorrhage. Our group’s earlier research showed that the best pressure of hyperbaric oxygen therapy in rats with cerebral hemorrhage is 2.0 ATA(Atmosphere absolute,ATA), and the best treated with hyperbaric oxygen in treatment of intracerebral hemorrhage is 6 hours.This topic is based on the preliminary studies of our group’s and with them,we discuss the effects of different inhale oxygen time of hyperbaric oxygen on perihematomal edema and expression of aquaporin-4 and superoxide dismutase in rats with intracerebral hemorrhage,for exploring the best inhale oxygen time of hyperbaric oxygen intervene ICH.Methods: 1 Animal groups: 125 Wistar male rats(except the model was not successful), and weight in 245g~265g, offered by the Hebei Medical University laboratory animal Center, cage in the second Hospital of Hebei Medical University, Neurology, laboratory animal room, fed with standard diet and drinking tap water. Randomly divided into two groups(100) and control group(25).According to different stable oxygen time, experimental group was divided into different inhale oxygen time 40 min,60min,80 min and 100 min 4 subgroups, each group of 25 Wistar rats had HBO treatment after 6h of intracerebral hemorrhage, pressure was 2.0ATA,1/d. Take 5 in each group only executed after HBO treatment of 1d,3d,5d,7d and 14 d respectively, collecting specimens after death. Control group is a total of 25, after intracerebral hemorrhage under normal circumstances, no treatment, the death time is same as the experimental group, collecting specimens after death. 2 Preparation of animal model: The rat model of ICH was established bycollagenase-induced method 3 Neural function of assessment: The neurologic defect for the rat models of ICH induced by collagenase after 6 hours was evaluated by Longa FZ scoring method. No sign was rated as 0 point. The contralateral body of inserting needle could not be fully extended was denoted by 1 point. The injury side limb was palsy with tailgating phenomenon was denoted by 2 points. Rats that appeared hemiparalysis symptoms was denoted by 3 points. If the rats loss of consciousness the score was denoted by 4 ponts. The Longa FZ score above 2 points, the ICH models can be taken to the experiment. 4 Hyperbaric oxygen therapy: hyperbaric oxygen in postoperative 6h to treat when scoring to determine the successful model. Placed animal to special wooden placewith high-pressure oxygen, pressure set for 2.0ATA, pressurized 30 min, before stable time 5 minutes used straight row type to animal box filling oxygen, oxygen flow set for 10L/min(stable time measuring oxygen concentration can up to 85%), stable oxygen time according to experiment group(40min, and 60 min, and 80 min, and 100min) set, then decompression 20 min,1 times/d. 5 Proportion of wet and dry method for the determination of water content of brain,Immuno-Histochemical determination ABC for perihematomal of intracerebral hemorrhage to test AQP4 expression levels,determination of SOD by Xanthine oxidase, strictly according to the instruction.Results: 1 Changes of water content of brain in rats: the result of perihematomal of the brain water content determination: from ICH we can see that in the control group, and water content in brain of rats after ICH begins to rise at ICH 1std, 3rdd to the peak, then gradually declined. No significant difference between the subgroups of control group(P>0.05), but the experimental groups compare with the control groups, they at each time point were reduced and have differences in brain water content(P<0.05). but between the 4 subgroups of the HBO therapy their water content in brain don’t have significantdifference(P>0.05), see Table 1. 2 AQP4 in the control group of rats in postoperative 1std of ICH begins to rise, 3rdd has significantly increased, 5thd to the peak and then gradually declined until 14 thd. A significant difference between the groups(P<0.05). Expression of AQP4 at each time point in the HBO experimental groups compare with the control groups, there was a statistically significant difference(P<0.05). Comparison between HBO experimental groups:The trend of each group is roughly same to the control group, but the overall trend is lower than the control group. At 7thd AQP4 began to fall, and continued to fall to 14 thd. Minimum value of AQP4 in each group appears at 14 thd, ICH+HBO60min group has the largest decline at 7thd, values of AQP4 compare with the other three groups at 7thd has a statistically significant difference(P<0.01). Expression of AQP4 in the 14 thd group of ICH+HBO60min group compare to ICH+HBO40min group 14 thd group,ICH+HBO100min group 14 thd group there was a statistically significant difference(P<0.01), but compare with the ICH+HBO80min group 14 thd group there was no significant difference(P>0.05), and the rest group had no significant statistical differences between each other(P>0.05), see Table 2. 3 We can observe SOD expression of control groups in the brain of ICH rat at 1std, but apparent decline in 3rdd, expression of 5thd has rebounded, 7thd to 14 d, continue to rise. 3rdd group compare to 1d group, 5d group, there were statistical differences(P<0.05), no statistically significant difference between the rest subgroups(P>0.05).We can see from the data, Compared to the control groups, SOD expression recovery in the HBO experimental groups is largely the same, but rebounded relatively increased in the experimental groups,among various subgroups, mostly compared with 3rdd, 5thd group, expression of 14 thd group has a statistical significance(P<0.01). In the experimental groups, 3rdd to 5thd the SOD expression appears minimum value, but the decrease compared with the control groups is little, all at various time points of SOD expression in the experimental groups compare with the control groups have statistically significant differences(P<0.01). Between HBOexperiment groups: from SOD expression of value of changes trend we can see, ICH+HBO60min group from 5thd to 7thd and from 7thd to 14 thd have a big rise again than other experiment groups,the changes are maximum, its expression of value at 14 thd compare with other three groups has differences(P<0.01). The rest between each group has not obviously differences(P>0.05), see Table 3.Conclusions: Through the rat model of ICH was established by collagenase-induced method, 2.0 ATA pressure of HBO therapy, intracerebral hemorrhage in 6 hours,to explore the best inhale oxygen time therapy of hyperbaric oxygen on intracerebral hemorrhage, the results appear that intracerebral hemorrhage perihematomal around brain changes of water content and AQP4 expression has the same change, and has negative related to the changes of SOD expression. Hyperbaric oxygen in the treatment of intracerebral hemorrhage secondary treatment, especially for the treatment of perihematomal edema after intracerebral hemorrhage treatment,the early intervention can significantly reduce intracerebral after intracerebral hemorrhage treated by hyperbaric oxygen. HBO can reduce perihematomal edema and the best inhale oxygen time is 60 min. It may be related to possible mechanisms that reduce AQP4 expression and increased SOD level.