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Objective To investigate the effects of inhaling high concentration of hydrogen gas on the expressions of endoplasmic reticulum stress(ERS) related protein glucose regulated protein 78 (GRP78),Caspase-12 and the neural cell apoptosis and related proteins Bcl-2 and Bax in the rats with focal cerebral ischemia reperfusion(I/R) injury.Methods Seventy-two healthy SPF male Sprague-Dawley rats were selected and then randomly divided into the control group(Ⅰ:without any treatment),sham operation group (Ⅱ),cerebral IRI group (Ⅲ) and hydrogen gas treatment group (Ⅳ),18 cases in each group.Focal cerebral ischemia reperfusion injury (IRI) model was induced by using the suture-occluded method.The neurological deficits score (NDS) was assessed at 24 h after cerebral reperfusion in four groups.The cerebral infarction severity and size were detected by TTC staining and neuronal apoptosis of brain cortex were tested by TUNEL technique.The apoptosis index (AI) was calculated.Then the expressions of GRP78,Caspase-12,Bcl-2 and Bax were assessed by Western blot and immunohistochemistry.Results As compared with the group Ⅰ and Ⅱ,NDS score,cerebral infarction size,AI and the expressions of GRP78,Caspase-12 and Bax in cerebral cortex in the group Ⅲl and Ⅳ were significantly increased,while the expression of Bcl-2 in cerebral cortex was markedly decreased(P＜0.05);compared with the group Ⅲ,NDS score,brain infarction size,AI and the expression of Caspase-12 and Bax in cerebral cortex in the group Ⅳ were markedly decreased,while the expressions of GRP78 and Bcl-2 were dramatically increased (P＜0.05).Conclusion Inhaling high concentration of hydrogen gas has a certain protective effect on cerebral IRI in rats through increasing endoplasmic reticulum GRP78 protein expression after IRI and inhibiting Caspase-12 activation,thus inhibiting ERS and promoting the repair function of endoplasmic reticulum.
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Objective To investigate the role of phosphatidylinositol 3?kinase∕protein kinase B∕glycogen synthase kinase?3β ( PI3K∕Akt∕GSK?3β) signaling pathway in hydrogen?induced inhibition of neuronal ap?optosis induced by focal cerebral ischemia?reperfusion ( I∕R) in rats. Methods One hundred and twenty healthy adult male Sprague?Dawley rats, weighing 200-220 g, were divided into 5 groups ( n=24 each) u?sing a random number table: sham operation group ( group S); cerebral I∕R group ( group I∕R); hydrogen group (group H2); LY294002 (specific PI3K inhibitor) group (group LY); LY294002+hydrogen group ( group LY+H2 ) . Focal cerebral I∕R was induced by occlusion of the middle cerebral artery for 1 h followed by 24 h reperfusion. In H2 and H2+LY groups, the animals inhaled 67% H2+33% O2 for 2 h starting from onset of reperfusion, and then inhaled H2 for 2 h every 6 h. In LY and LY+ H2 groups, LY294002 ( 10 mmol∕L) 10 μl was injected into the lateral cerebral ventricle at 10 min before reperfusion. Neurologic defi?cit was evaluated and scored ( NDS) at 24 h of reperfusion. The rats were then sacrificed, and the brains were removed for measurement of the cerebral infarct size ( by TTC staining) and apoptosis in cortical neu?rons ( by TUNEL) and for determination of the expression of Akt in the ischemic cerebral cortex, phospho?rylated Akt ( p?Akt) , GSK?3β and phosphorylated GSK?3β ( p?GSK?3β) and Bcl?2 and Bax positive cell count in the ischemic cerebral cortex ( by immuno?histochemistry) . The apoptosis index ( AI) , p?Akt∕Akt ratio and p?GSK?3β∕GSK3?β ratio were calculated. Results Compared with group S, the NDS, cerebral infarct size, AI, p?Akt∕Akt ratio, p?GSK?3β∕GSK?3β ratio and Bax positive cell count were significantly increased, and the Bcl?2 positive cell count was significantly decreased in group I∕R ( P0?05) . Compared with group H2 , the NDS, cerebral infarct size, AI and Bax positive cell count were significantly increased, and the p?Akt∕Akt ratio, p?GSK?3β∕GSK?3βratio and Bcl?2 positive cell count were significantly decreased in group LY+H2 ( P<0?05) . Conclusion The mechanism by which hydrogen inhibits focal cerebral I∕R?induced neuronal apoptosis is associated with the activation of PI3K∕Akt∕GSK?3β signaling pathway in rats.
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Objective To investigate the effect of high concentration hydrogen gas on neurons in the rat hippocampus CA1 region during global cerebral ischemic/reperfusion injury (GCIR) Methods Four-vessel occlusion was used to establish rat model with GCIR injury. One hundred and five healthy male Sprague-Dawley rats were randomly divided into sham operation group(SH group, n = 15), model group(4-VO group, n = 45) and treatment group(4-VO+H2 group,n = 45). After 72 h and 9 d reperfusion, hippocampal CA1 region pyramidal neurons in every group were detected with Nissle staining , immunohistochemical neuron-specific nuclear protein (NeuN), specific protein antibody microglial cells (Iba1) staining and the relationship of position between neurons and microglia was observed through fluorescence double staining. We used Morris water maze to test the space orientation ability and the learning and memory ability in rats after 9 d reperfusion. Results Compared with those of 4-VO group,the neurons of hippocampus CA1 region were closer to normal in 72 h and 9 d in 4-VO+H2 group and neuron form and the number of neuron survival were increased significantly (P < 0.05);immunohistochemical staining showed that the number of neuron survival in 4-VO+H 2 group was obviously higher than that in 4-VO group (P < 0.05) and the number of microglia in 4-VO group was obviously higher than that in 4-VO+H2 group (P < 0.05). Water maze experiment showed that the swimming time in quadrant Ⅳ in 4-VO+H2 group was longer than that in 4-VO group (P < 0.05). Conclusion Inhalation of high concentration hydrogen gas has prominent protective effect on neurons of rat hippocampal CA1 region during reperfusion. The mechanism may be related with inhibiting the microglia excitation and activation during GCIR.
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Objective To evaluate the role of phosphoinositide 3 kinase/protein kinase B (PI3K/Akt) signaling pathway in hydrogen-induced inhibition of cell apoptosis during myocardial ischemia/reperfusion (I/R) in rats.Methods Forty healthy male Sprague-Dawley rats,weighing 300-350 g,were randomly allocated into 4 groups (n =10 each) using a random number table:sham operation group (S group),I/R group,hydrogen group (group H),and hydrogen + LY294002 group (group HL).Myocardial I/R was induced by occlusion of the anterior descending branch of left coronary artery for 30 min followed by 120 min reperfusion.In H and HL groups,99.6 ％ hydrogen 5 ml/kg was injected intraperitoneally immediately after beginning of reperfusion,and in addition LY294002 (0.3 mg/kg) was injected through the caudal vein before hydrogen injection in group HL.Arterial blood samples were collected at the end of 120 min reperfusion for determination of serum creatine kinase isoenzyme-MB (CK-MB) and lactate dehydrogenase (LDH) activities.The rats were then sacrificed.Myocardial apoptosis was detected by TUNEL and apoptosis index (AI) was calculated.The expression of Bcl-2,Bax and caspase-3 was detected by immuno-histochemistry.Bcl-2/Bax ratio was calculated.Results The serum CK-MB and LDH activities and AI were significantly increased,the expression of myocardial Bcl-2,Bax and caspase-3 was upregulated,and the ratio of Bcl-2/Bax was decreased in group I/R as compared with group S.Compared with group I/R,the serum CK-MB and LDH activities and AI were significantly decreased,the expression of myocardial Bcl2 was up-regulated,while the expression of myocardial Bax and caspase-3 was down-regulated,and the ratio of Bcl-2/Bax was increased in group H,and no significant changes were found in the parameters mentioned above in group HL.The serum CK-MB and LDH activities and AI were significantly increased,the expression of myocardial Bcl-2 was down-regulated,while the expression of myocardial Bax and caspase-3 was up-regulated,and Bcl-2/Bax ratio was decreased in group HL as compared with group H.Conclusion Hydrogen can activate the PI3K/Akt signaling pathway,and further up-regulates Bcl-2 expression and down-regulates Bax and Caspase-3 expression,thus inhibiting cell apoptosis during myocardial I/R in rats.