Effects And Mechanisms Of Hyperbaric Oxygen With Different Pressure For Moderate To Severe Traumatic Brain Injury

Part 1Effects of Hyperbaric Oxygen with different pressure for moderate to severe traumatic brain injuryObjective:To compare the effects of early hyperbaric oxygen(HBO)with different pressures on rats with moderate to severe traumatic brain injury(TBI).Methods:Seventy-five male adult Sprague-Dawle rats,250 g-300 g,were randomly divided into five groups:blank control group;Traumatic brain injury group(TBI group): The moderate and severe TBI model in rats was established by controlled cortical impact(CCI)using PCI3000 accurate brain impactor and;Sham operation group(sham group): Only open the skull,no head strike;1.5 absolute atmospheric pressure hyperbaric oxygen treatment group(1.5ATA HBO+TBI group):1.5 ATA hyperbaric oxygen treatment was given on the basis of the TBI group;2.5 absolute atmospheric pressure hyperbaric oxygen treatment group(2.5ATA HBO+TBI group):2.5 ATA hyperbaric oxygen treatmen was given on the basis of the TBI group;All rats were subjected to modified neurological severity score(m NSS)day 1(D1),day 3(D3),and day 7(D7)respectively;We selected three high-signal regions on the magnetic resonance DWI image as the ROI region,and measured the Apparent Diffusion Coefficient(ADC),The ratio of the lesion side to the normal contralateral ADCwas compared,thatis,the relative ADC(r ADC).Observe and record the recovery of rats in each group and compare the recovery differences.SPSS19.0 and Graph Pad Prism6.0 were used for statistical analysis,and P< 0.05 showed that the difference was statisticallysignificant.Results:1 m NSS scores of rats in each groupon D1,TBI group,1.5ATA group and 2.5ATA group,there was no significant difference in m NSS score(P>0.05),which was significantly higher than that of sham group(P<0.05),the m NSS scores in the 2.5ATA and1.5ATA groups gradually decreased and were lower than those in the TBI group(P<0.05),but there was no significant difference between 1.5ATA and2.5ATA(P> 0.05).(Pre-experimental results show that there is no significantlydifference between sham group and control group.)2 MRI ADC results of rats in each groupon D1,the r ADC values of different ROIs in each group were not statistically significant(P>0.05);on D3,the r ADC values of different ROIs in 1.5ATA HBO and 2.5ATA HBO groups were lower than those in TBI group(P< 0.05),higher than Sham group(P<0.05),there was no significant difference between 1.5ATA HBO and 2.5ATA HBO groups(P>0.05);on D7,the r ADC values of different ROIs in 1.5ATA HBO and 2.5 ATA HBO group were lower than TBI group(P< 0.05),there was no significant difference compared with Sham group(P>0.05),there was no significant difference between 1.5ATA HBOand 2.5 ATA HBO groups(P>0.05).(Pre-experimental results show that there is no significantlydifference between sham group and control group.)Conclusion:Early hyperbaric oxygen has a definitive effect on the recovery of neurological function in rats with moderate to severe traumatic brain injury.However,the treatment pressure of HBO may not be the key factor in determining prognosis.Part 2 The Mechanism of Different Pressure Hyperbaric Oxygen on Moderate and Severe Traumatic Brain InjuryObjective:To explore the mechanism of early different pressure hyperbaric oxygen(HBO)in the treatment of moderate and severe traumatic brain injury(TBI)rats.Methods:Seventy-five male adult Sprague-Dawle rats,250 g-300 g,were ran domly divided into five groups: blank control group;Traumatic brain inj ury group(TBI group): The moderate and severe TBI model in rats w as established by controlled cortical impact(CCI)using PCI3000 accurat e brain impactor and;sham operation group(sham group): Only open t he skull,no head strike;1.5 absolute atmospheric pressure hyperbaric ox ygen treatment group(1.5ATA HBO+TBI group):1.5 ATA hyperbaric oxy gen treatment was given on the basis of the TBI group;2.5 absolute atm ospheric pressure hyperbaric oxygen treatment group(2.5ATA HBO+TBI group):2.5 ATA hyperbaric oxygen treatmen was given on the basis of the TBI group;All rats were collected with tail vein blood on the first day(D1),the third day(D3),and the seventh day(D7),and enzyme-lin ked immunosorbent assay(ELISA)was used to detect the expression of IL-1β,IL-10,SOD,BDNF and S100β in rat serum and brain tissue;A ll rats were decapitated on the first day(D1),the third day(D3)and the seventh day(D7)after operation,respectively.Immunohistochemical flu orescence was used to observe the expression of S100β and BDNF on t he injured side of rats,and Western blot was used to detect the express ion of BDNF and p75.SPSS19.0 and Graph Pad Prism6.0 were used for statistical analysis,and P< 0.05 showed that the difference was statistica lly significant.Results:1 Expression of IL-1β,IL-10,SOD,BDNF and S100β in rats of each group(Pre-experimental results show that there is no significantlydifference between sham group and control group)1.1 on D1,the levels of IL-1β in serum and brain tissues of rats in TBI group,1.5ATA group and 2.5ATA group were significantly higher than those in sham group(P< 0.05);on D3 and D7,the content of IL-1β in serum and brain tissue of rats in 1.5ATA group and 2.5ATA group was lower than that in TBI group(P<0.05),and there was no difference between 1.5ATA group and2.5ATA group(P>0.05);1.2 on D1,the levels of IL-10 in serum and brain tissues of rats in TBI group,1.5ATA group and 2.5ATA group were higher than those in sham group(P<0.05);on D3 and D7,the levels of IL-10 in serum and brain tissues of rats in 1.5ATA group and 2.5ATA group are higher than those in TBI group(P<0.05),but the levels of IL-10 in brain tissues of rats in 1.5ATA group are higher than those in 2.5ATA group on D3 and D7,and the levels of IL-10 in serum are higher than those in 2.5ATA group only on D7(P< 0.05);1.3 on D1 and D3,SOD content in serum and brain tissue of rats in TBI group,1.5ATA group and 2.5ATA group is not significantly different from that of sham group(P>0.05),while SOD content in serum and brain tissue of rats in D7 and 1.5ATA group is significantly higher than that of2.5ATA group(P<0.05).1.4 on D1 and D3,there was no significant difference in BDNF content in brain tissue of rats in each group(P>0.05),on D7,1.5ATA and2.5ATA,BDNF level in brain tissue of rats was higher than that of TBI group(P<0.05),and there was no statistical significance between 1.5ATA group and 2.5ATA group(P>0.05);1.5 on D1,the content of S100β in brain tissue of rats in TBI group,1.5ATA group and 2.5ATA group is higher than that of sham group(P<0.05),on D3 and D7,the content of S100β in brain tissue of rats in1.5ATA group and 2.5ATA group is lower than that of TBI group,and there is no statistical significance between 1.5ATA group and 2.5ATA group(P>0.05).2 Immunohistochemical results of rats in each group(Pre-experimental results show that there is no significantlydifference between sham group and control group)2.1 S100β is widely expressed in rat hippocampus,but the expression intensity is low;on D1,the S100β fluorescence expression intensity of hippocampal region of TBI group,1.5ATA group and 2.5ATA group rats increased,but no significant change was found in control group and Sham group;on D3 and D7,the S100β fluorescence expression intensity in the hippocampal region of the TBI group rats did not decrease significantly,while the S100β fluorescence expression intensity in the brain tissues of the1.5ATA group and the 2.5ATA group decreased,but there was no significant difference between the two groups.2.2 BDNF expression is widely expressed in rat cortex and hippocampus,but the expression intensity is low;on D1,the expression levels of BDNF in the injured cortex and hippocampus of the TBI group,the1.5ATA group and the 2.5ATA group were reduced,while the control group and the Sham group showed no significant changes;on D7,the expression of BDNF in the injured cortex and hippocampus of the TBI group was still significantly lower than that of the control group,while the expression of BDNF in the injured cortex and hippocampus of the 1.5ATA and 2.5ATA groups was significantly higher than that of the TBI group,but there was no significant difference between the two groups.3 Expression of BDNF and p75 in each group of rats In order to further study the signaling pathways of hyperbaric oxygen to promote neural repair,we pay attention to the selection of BDNF-P75 receptor signaling pathways.It was found that BDNF and p75 expressions of D1 and D7 in the sham group were not significantly changed;on D1,the expressions of BDNF and P75 in TBI group,1.5ATA group and 2.5ATA group were slightly lower than those in control group and sham group;on D7,the expressions of BDNF and P75 in the TBI group were not significantlychanged compared to D1,while the expressions of BDNF and P75 in the1.5ATA and 2.5ATA groups were significantly higher than those on D1,and higher than TBI group;There was no significant difference in the expression levels of BDNF and P75 on D7,1.5ATA group and 2.5ATA group.Conclusion:Early hyperbaric oxygen therapy can alleviate neuroinflammatory and oxidative stress responses in rats with moderate to severe traumatic brain injury,up-regulate the expression of neurotrophic factors,and thereby promote neurological recovery.There is no obvious difference in alleviating inflammatory reaction,relieving and nerve injury and promoting nerve repair in rats with moderate or severe traumatic brain injurywith high and low pressur pressures Hyperbaric oxygen,but low pressure hyperbaric oxygen has the ability to improve the anti-neuroinflammation and anti-oxidation injury in rats.