高浓度氢气吸入对大鼠局灶性脑缺血再灌注损伤脑皮质神经细胞凋亡及凋亡相关蛋白表达的影响

目的：探讨吸入高浓度氢气对局灶性脑缺血再灌注（ I／R）损伤大鼠脑皮质神经细胞凋亡及凋亡相关蛋白Bcl－2和Bax表达的影响。方法48只健康雄性SD大鼠，随机分为假手术组（ Sham 组）、脑I／R损伤组（I／R组：再灌注同时吸入67％N2＋33％O2）、氢气（H2）治疗组（H2组：再灌注同时吸入67％H2＋33％O22 h），每组16只。使用线栓法建立大鼠局灶性脑I／R损伤模型。再灌注24 h后行神经功能缺损评分，采用TTC染色法观察大鼠脑梗死严重程度并计算其梗死面积，尼氏染色和TUNEL技术检测大鼠脑皮质神经细胞凋亡情况并计算凋亡指数（AI），蛋白质印迹法检测脑皮质区Bcl－2及Bax蛋白表达。结果与Sham组比较，I／R组、H2组神经功能缺损评分、脑梗死面积、AI、Bax蛋白表达明显增加（P＜0．05）；与I／R组比较，H2组大鼠神经功能缺损评分、脑梗死面积、AI、Bax蛋白表达明显降低，神经元尼氏体增加，Bcl－2表达量明显增多（P＜0．05）。结论再灌注同时吸入高浓度H2可通过上调抑凋亡蛋白Bcl－2及下调促凋亡蛋白Bax的表达抑制神经细胞凋亡，明显减少大鼠脑梗死面积，改善大鼠脑I／R后的神经功能评分，对大鼠脑I／R损伤起到一定的保护作用。

Effects of inhaling high concentrations hydrogen gas on neuronal apoptosis and the expression of apoptosis related proteins in the cortical region of rats with cerebral ischemia-reperfusion injury

Objective To investigate the effects of inhalation of high concentrations hydrogen gas on neuronal ap -optosis and the expressions of apoptosis -related proteins Bcl -2 and Bax on focal cerebral ischemia reperfusion injury in rats.Methods Forty-eight healthy male SD rats were randomly divided into 3 groups (n=16), sham-operated group (sham group), ischemia-reperfusion group (I/R group, during reperfusion inhaled 67%N2 +33%O2) and inhalation of hydrogen group (H2 group, during reperfusion inhaled 67%H2 +33%O2).Middle cerebral artery occlusion (MCAO) model was constructed using conventional method .Neurological severity score was evaluated 24 h after cerebral reperfusion in all groups .The cerebral infarction severity and volume were assessed by TTC staining , and neuronal apoptosis of brain cortex was examined by Nissl stain and TUNEL technique .The expressions of Bcl -2 and Bax were assessed with Western blot.Results As compared with sham group , the neurological deficit score , brain infarction volume , apoptosis index (AI) and the expression of Bax in I/R group and H2 group were significantly increased (P<0.05).Compared with I/R group, the neurological deficit score , brain infarction volume , apoptosis index and the expression of Bax in H 2 group were markedly decreased , while the expression of Bcl -2 was dramatically increased , and so was the quantity of Nissel′s body (P<0.05).Conclusion High concentration hydrogen during reperfusion can protect the I /R rats by reducing the size of cerebral infarction , ameliorating the neurological deficit and neuron apoptosis , and which may be related with up -regula-ting Bcl-2 and down-regulating Bax .