高压氧对创伤性脑水肿脑组织单胺递质变化的影响

Effects of hyperbaric oxygenation on monoamine neurotransmitter in cerebral edema induced by traumatic brain injury in rats

目的:探讨高压氧治疗对创伤性脑水肿形成和发展中的中枢单胺神经递质的影响。探讨大鼠颅脑创伤后高压氧对脑水肿及脑组织单胺递质变化的影响。方法:实验于2004-01/04在大坪医院野战外科研究所完成。将大鼠随机分为正常组、脑创伤组和高压氧治疗组,采用BIM-Ⅲ型撞击机撞击大鼠右侧颅顶,复制闭合性颅脑损伤,分别于伤后3,6及24h,应用高效液相法测定脑组织肾上腺素、去甲肾上腺素、多巴胺、5-羟色胺(5-hydroxytryptamine,5-HT)含量及干湿重法测定脑组织含水率。结果:①创伤组伤侧脑组织伤后6h去甲肾上腺素、多巴胺、5-HT显著升高分别为(2946±686)ng/g,(2341±542)ng/g,(904±150)ng/g(P<0.05);24hNE达高峰(3523±1276)ng/g(P<0.01),5-HT较6h有所下降(752±203)ng/g但仍高于对照组(P<0.05),多巴胺降至正常水平。脑损伤后伤侧脑组织肾上腺素含量在各时相点均无统计学意义。高压氧组在6h、多巴胺、5-HT显著升高[分别为(2284±395)ng/g,(758±142)ng/g,P<0.01,<0.05),24h多巴胺低于对照组(1050±576)ng/g,P<0.05];去甲肾上腺素在6h开始升高,24h达高峰[(3061±939)ng/g,P<0.05]。②创伤组与高压氧组相比,高压氧组肾上腺素、去甲肾上腺素、多巴胺、5-HT含量在各时间点均低于创伤组,仅有多巴胺。

AIM: To investigate the effect of hyperbaric oxygen(HBO) on monoamine neurotransmitters during the formation and development of cerebral edema induced by traumatic brain injury(TBI). METHODS:The experiment was completed in the Institute of Field%Surgery,DA ping Hospital between January 2004 and April 2004. The rats were randomized into control group,TBI group(BI), and HBO group.A model of closed crania cerebral injury, induced by using the BIM Ⅲbio impact machine to attack the right top of skull of the rats, was established. Then, samples were acquired by drawing blood from the heart at 3,6,24 hours after injury, and the concentrations of adrenalin(A),5 hydroxytryptamine(5 HT), noradrenatin(NA) and dopamine(DA) in brain of each group were measured respectively with high pressure liquid chromatography (HPLC).At the same time, the ratio of brain water content was determined by method of dry/wet. RESULTS: ①Contents of NE, DA, and 5 HT in the injured brain tissue of TBI group were significantly increased to(2 946±686), (2341±542), and(904±150) ng/g respectively at 6 hours after TBI. At 24 hours after TBI, the contents of NE reached the peak[(3 523±1 276) ng/g]; the content of 5 HT[(752±203) ng/g] decreased gradually, but was still higher than that of the control group(P< 0.05);the content of DA decreased to the normal level. There was no significant difference in the contents of A among the three groups. In the HBO group, the contents of DA, 5 HT at 6 hours after TBI were significantly increased to(2 284±395) and(758±142) ng/g respectively(P< 0.01, P< 0.05), and the content of DA at 24 hours was significantly lower than that of the control group[(1 050±576) ng/g, P< 0.05]; the content of NE began to increase in 6 hours after TBI, and reached the peak at 24 hours[(3 061±939) ng/g, P < 0.05]. ②Compared with the TBI group, the contents of A, NE, DA, 5 HT were lower at different time, but only the contents of DA and 5 HT[(1 050±576) and(450±122) ng/g] were significantly lower at 24 hours after TBI(P< 0.05 and P< 0.01).③The rate of water content in the brain tissue was significantly higher in the TBI and HBO groups than in the control group at different time[(78.66±0.24)%,(78.92±0.29)%and(79.08±0.33)%], and it was significantly lower in the HBO than in the TBI group at 24 hours(P< 0.01), but there was no significant difference between the HBO and TBI groups at 3 to 6 hours after injury. CONCLUSION: Over expression of monoamine neurotransmitter in brain is an important factor for development of cerebral edema after TBI. HBO can improve hypoxia, and reduce level of 5 HT, NE, DA in brain tissue, and alleviate cerebral edema.