不同浓度氢气对肠缺血/再灌注大鼠生存率及认知功能的影响

Effect of different concentrations of hydrogen on survival rate and cognitive function of rats after intestinal ischemia/reperfusion

目的:观察不同浓度氢气(H2)对肠缺血/再灌注(I/R)大鼠生存率及认知功能的影响,探讨相关机制。方法:将SD大鼠176只随机分为4组(n=44):假手术(Sham)组、肠缺血/再灌注(I/R)组、I/R+2%H2组和I/R+4%H2组。采用夹闭肠系膜上动脉(SMA)90 min再灌注的方法制备大鼠肠I/R模型。H2组于再灌注即刻吸入2%或4%氢气3 h。观察各组大鼠7 d生存率,用Morris水迷宫评定大鼠认知功能。采用免疫荧光观察脑小胶质细胞活性,酶联免疫吸附(ELISA)法检测血中神经元特异性烯醇化酶(NSE)、S100β含量及皮质白细胞介素(IL)-1βIL-6及肿瘤坏死因子(TNF)-α含量。结果:与Sham组比较,I/R组及H2各组大鼠7 d生存率下降;平均逃避潜伏期延长,穿越平台次数及平台象限停留时间减少;小胶质细胞活性、NSE、S100β、IL-1β、IL-6及TNF-α含量增加;差异均具有统计学意义(P<0.05)。与I/R组比较,I/R+2%H2组和I/R+4%H2组生存率提高;平均逃避潜伏期缩短,穿越平台次数及平台象限停留时间增加;小胶质细胞活性、NSE、S100β、IL-1β、IL-6及TNF-α含量降低;差异均具有统计学意义(P<0.05)。结论:不同浓度氢气(2%及4%)均能改善肠缺血/再灌注(I/R)大鼠生存率及认知功能的变化,机制可能与抑制小胶质细胞激活,减轻神经炎症反应有关。

Objective： To investigate the effect of different concentrations of hydrogen （H2） on survival rate and cognitive function of rats after intestinal ischemia/reperfusion （I/R） and possible mechanisms. Methods： A total of 176 Sprague-Dawley rats were randomly divided into sham-operation group （Sham group）, intestinal I/R group （I/R group）, I/R＋2% H2 group, and I/R ＋ 4% H2 group, with 44 rats in each group. A rat model of intestinal I/R was established by clamping of the superior mesenteric artery for 90 min followed by reperfusion. The rats in the I/R ＋ 2% H2 group and the I/R ＋ 4% H2 group were given inhalation of 2% or 4% H2 for 3 hours immediately after reperfusion. The 7-day survival rate was observed, and Morris water maze was used to evaluate cognitive function. Immunofluorescence assay was used to observe the activity of microglial cells and ELISA was used to measure the levels of neuron-specific enolase（NSE） and S10015 in blood and the levels of interleukin-1 β （IL-1β）, interleukin-6 （IL-6）, and tumor necrosis faetor-α （TNF-α） in the cortex. Results： Compared with the Sham group, the I/R group, the UR ＋ 2% H2 group, and the UR＋4% H2 group had a significant reduction in the 7-day survival rate （P 〈 0.05）, a significant increase in escape latency （P 〈 0.05）, significant reductions in the number of platform crossings and the time spent in target quadrant （P 〈 0.05）, and significant increases in the activity ofmicroglial cells and the levels of NSE, S100β, IL-1β, IL-6, and TNF-α （P 〈 0.05）. Compared with the I/R group, the I/R＋2% H2 group and the I/R ＋ 4% H2 group had a significant increase in the 7-day survival rate （P 〈 0.05）, a significant reduction in escape latency （P 〈 0.05）, significant increases in the number of platform crossings and the time spent in target quadrant （P 〈 0.05）, and significant reductions in the activity of microglial cells and the levels of NSE, S100β, IL-1β, IL-6, and TNF-α （P 〈 0.05）. Conclusions： Different concentrations of H2 （2% or 4%） can improve the survival rate and cognitive function of rats with intestinal I/R, possibly by inhibiting the ac- tivation of microglial cells and alleviating neurointlammation.