富氢液联合浅低温对大鼠脑缺血再灌注海马氧化应激水平的影响

Effect of hydrogen-rich saline in combination with mild hypothermia on hippocampal oxidative stress in rats with global cerebral ischemia-reperfusion injury

目的在脑缺血再灌注过程中,富氢液和浅低温均可影响机体的氧化应激水平。探讨腹腔注射富氢液联合浅低温对大鼠脑缺血再灌注海马氧化应激水平的影响。方法 50只雄性SD大鼠随机分为5组(n=10):假手术组(S组)、四血管结扎模型组(C组)、富氢液+模型组(W组)、浅低温+模型组(P组)和低温+富氢液+模型组(WP组)。W和WP组在脑缺血再灌注即刻腹腔注射富氢液5 ml/kg,S、P和C组注射等容量等渗盐水。P和WP组通过全身物理降温15 min内将体温降至目标温度32～34℃,维持6 h,其余3组维持在37～38℃。所有大鼠在缺血再灌注6 h时处死,分离海马。苏木精-伊红染色(HE染色),观察海马神经元形态;免疫组化法观察血红素氧合酶-1(heme oxygenase-1,HO-1)的表达;化学分光光度计法测海马谷胱甘肽过氧化物酶(glutathion eperoxidase,GSH-Px)和髓过氧化物酶(myeloperoxidase,MPO)活性。结果与C组比较,P、W和WP组海马神经元结构排列紧凑、变性神经元减少;海马HO-1免疫阳性细胞增多。与C组比较,P、W、和WP组MPO含量降低(P<0.05),GSH-Px含量增高(P<0.05),WP组变化最明显。结论富氢液联合浅低温治疗可通过诱导海马HO-1蛋白表达、降低MPO和上调GSH-Px活性影响大鼠全脑缺血再灌注损伤氧化应激水平。

Objective During cerebral ischemia-reperfusion,hydrogen-rich saline and mild hypothermia could affect the level of oxidative stress.Our experiment aims to investigate the effect of hydrogen-rich saline in combination with mild hypothermia on the level of hippocampus oxidative stress in rats with global cerebral ischemia-reperfusion injury.Methods Fifty male SD rats were randomly divided into 5 groups of equal number： sham operation（S）,model（C）,hygrogen-rich saline＋model（W）,mild hypothermia＋model（P）,and mild hypothermia＋hydrogen-rich saline＋model（WP）.The rats in the W and WP groups received intraperitoneal injection of hydrogen-rich saline at 5 ml/kg immediately after ischemia-reperfusion,while those in the other three groups received the same volume of saline.The body temperature of the rats in the W and WP groups was cooled down by the physical method to 32-34 ℃ within 15 minutes and maintained at it for 6 hours,while that of the other three groups kept at 37-38 ℃.All the animals were killed 6 hours after cerebral ischemia-reperfusion,and the hippocampus removed.The morphology of the hippocampal neuron was observed by HE staining,the expression of HO-1 detected by immunohistochemistry,and the activities of glutathion eperoxidase（GSH-Px） and myeloperoxidase（MPO） measured by chemical spectrophotometry.Results Compared with the C group,the W,P and WP groups showed compact arrangement of hippocampal neuron,less denatured neurons,more HO-1 immunopositive cells,lower content of MPO（P0.05）,and higher expression of GSH-Px（P0.05）.Conclusion Hydrogen-rich saline and mild hypothermia can influence the oxidative stress level of the hippocampus in rats with global cerebral ischemia-reperfusion injury by inducing the expression of HO-1,decreasing that of MPO and increasing the activity of GSH-Px.