An improved 4-vessel intermittent occlusion method for establishing rat models of global cerebral ischemia-reperfusion injury / 南方医科大学学报

OBJECTIVE@#To improve the classical 4-vessel occlusion (4VO) model established by Pulsinelli and Brierley.@*METHODS@#Thirty-two male SD rats were randomized into sham operation group, I4VO-Con10 group, I4VO-Int10 group and I4VO-Int15 group. The sham surgery group underwent exposure of the bilateral vertebral arteries and carotid arteries without occlusion to block blood flow. The I4VO-Con10 group experienced continuous ischemia by occluding the bilateral vertebral arteries and carotid arteries for 10 minutes followed by reperfusion for 24 hours. The I4VO-Int10 and I4VO-Int15 groups were subjected to intermittent ischemia. The I4VO- Int10 group underwent 5 minutes of ischemia, followed by 5 minutes of reperfusion and another 5 minutes of ischemia, and then reperfusion for 24 hours. The I4VO-Int15 group experienced 5 minutes of ischemia followed by two cycles of 5 minutes of reperfusion and 5 minutes of ischemia, and then reperfusion for 24 hours. The regional cerebral blood flow (rCBF) was monitored with laser Doppler scanning, and survival of the rats was observed. HE staining was used to observe hippocampal pathologies to determine the optimal method for modeling. Another 48 rats were randomized into 6 groups, including a sham operation group and 5 model groups established using the optimal method. The 5 I4VO model groups were further divided based on the reperfusion time points (1, 3, 7, 14, and 28 days) into I4VO-D1, I4VO-D3, I4VO-D7, I4VO- D14, and I4VO- D28 groups. Body weight changes and survival of the rats were recorded. HE staining was used to observe morphological changes in the hippocampal, retinal and optic tract tissues. The Y-maze test and light/dark box test were used to evaluate cognitive and visual functions of the rats in I4VO-D28 group.@*RESULTS@#Occlusion for 5 min for 3 times at the interval of 5 min was the optimal method for 4VO modeling. In the latter 48 rats, the body weight was significantly lower than that of the sham-operated rats at 1, 3, 7, 14 and 28 days after modeling without significant difference in survival rate among the groups. The rats with intermittent vessel occlusion exhibited progressive deterioration of hippocampal neuronal injury and neuronal loss. Cognitive impairment was observed in the rats in I4VO-D28 group, but no obvious ischemic injury of the retina or the optic tract was detected.@*CONCLUSION@#The improved 4VO model can successfully mimic the main pathological processes of global cerebral ischemia-reperfusion injury without causing visual impairment in rats.

Effects of pramipexole combined with levodopa on cognitive and mitochondrial function of rats after global cerebral ischemia-reperfusion injury / 中国康复理论与实践

ObjectiveTo investigate the effects of dopamine receptor agonist pramipexole and levodopa on emotion and cognition, and mitochondrial membrane potential of rats after global cerebral ischemia-reperfusion injury. MethodsA total of 80 male Sprague-Dawley rats were divided into sham group (n = 20), model group (n = 20), pramipexole group (n = 20) and combined group (n = 20). The latter three groups were used to prepare the model of global cerebral ischemia-reperfusion injury with Pulsinelli's four-vessel occlusion. The pramipexole group was intraperitoneally injected pramipexole 0.5 mg/kg once a day, while the combined group was injected levodopa 50 mg/kg and pramipexole 0.5 mg/kg, for 14 days. Five rats in each group were tested with open field test three, seven and 14 days after modeling; five were tested with Y-maze test seven and 14 days after modeling; five were detected mitochondrial membrane potential three, seven and 14 days after modeling; and five were observed under Nissl's staining14 days after modeling. ResultsCompared with the model group, the number of entries into the central zone (P < 0.05), total distance travelled (P < 0.05) and average velocity (P < 0.05) in the open field test increased in the pramipexole and combined groups seven and 14 days after modeling, duration spent in the central zone increased in the pramipexole and combined groups seven days after modeling (P < 0.05); the rate of spontaneous alternation of Y-maze test increased in the pramipexole and combined groups 14 days after modeling (P < 0.05); mitochondrial membrane potential in hippocampus increased in the pramipexole and combined groups seven and 14 days after modeling (P < 0.05), and it was less in the pramipexole group than in the combined group 14 days after modeling (P < 0.05); and the number of surviving neurons in the hippocampal CA1 increased in the pramipexole and combined groups 14 days after modeling (P < 0.05). ConclusionPramipexole may improve emotion and cognition of rats after global cerebral ischemia-reperfusion injury, and it may be helpful for restoring mitochondrial membrane potential as combining with levodopa.

Blockade of HCN2 Channels Provides Neuroprotection Against Ischemic Injury via Accelerating Autophagic Degradation in Hippocampal Neurons / 神经科学通报·英文版

In the central nervous system, hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are essential to maintain normal neuronal function. Recent studies have shown that HCN channels may be involved in the pathological process of ischemic brain injury, but the mechanisms remain unclear. Autophagy is activated in cerebral ischemia, but its role in cell death/survival remains controversial. In this study, our results showed that the HCN channel blocker ZD7288 remarkably decreased the percentage of apoptotic neurons and corrected the excessive autophagy induced by oxygen-glucose deprivation followed by reperfusion (OGD/R) in hippocampal HT22 neurons. Furthermore, in the OGD/R group, p-mTOR, p-ULK1 (Ser), and p62 were significantly decreased, while p-ULK1 (Ser), atg5, and beclin1 were remarkably increased. ZD7288 did not change the expression of p-ULK1 (Ser), ULK1 (Ser), p62, Beclin1, and atg5, which are involved in regulating autophagosome formation. Besides, we found that OGD/R induced a significant increase in Cathepsin D expression, but not LAMP-1. Treatment with ZD7288 at 10 μmol/L in the OGD/R group did not change the expression of cathepsin D and LAMP-1. However, chloroquine (CQ), which decreases autophagosome-lysosome fusion, eliminated the correction of excessive autophagy and neuroprotection by ZD7288. Besides, shRNA knockdown of HCN2 channels significantly reduced the accumulation of LC3-II and increased neuron survival in the OGD/R and transient global cerebral ischemia (TGCI) models, and CQ also eliminated the effects of HCN2-shRNA. Furthermore, we found that the percentage of LC3-positive puncta that co-localized with LAMP-1-positive lysosomes decreased in Con-shRNA-transfected HT22 neurons exposed to OGD/R or CQ. In HCN2-shRNA-transfected HT22 neurons, the percentage of LC3-positive puncta that co-localized with LAMP-1-positive lysosomes increased under OGD/R; however, the percentage was significantly decreased by the addition of CQ to HCN2-shRNA-transfected HT22 neurons. The present results demonstrated that blockade of HCN2 channels provides neuroprotection against OGD/R and TGCI by accelerating autophagic degradation attributable to the promotion of autophagosome and lysosome fusion.

Neuregulin 1/ErbB4 signaling attenuates neuronal cell damage under oxygen-glucose deprivation in primary hippocampal neurons / 대한해부학회지

Effect of total saponins of Panax notoginseng on learning and memory of global cerebral ischemia rats and its mechanism / 中草药

Objective: To explore the effect of the total saponins of Panax notoginseng (TSPN) on learning and memory of global cerebral ischemia rats and its mechanism. Methods: Using four-vessel occlusion method to establish the global cerebral ischemia model. Rats were divided into sham group, vehicle group, and TSPN group. The rats in the TSPN group were administered TSPN intraperitoneally 30 min post-brain ischemia. The dose of TSPN (75 mg/kg) was suspended in 0.9% saline 10 g/L, once per day for 14 d after reperfusion. Rats in the vehicle group were treated with equal volume of 0.9% saline, one injection per day for 14 d. The Morris Water Maze was performed to test the learning and memory of rats and doublecortin (DCX) and NeuN expression in the hippocampus was assessed by immunohistochemistry. Furthermore, immunoblotting was adopted to test the protein level of DCX in the CA1 subfield of hippocampus. Results: The escape latency in the vehicle group was longer than that in the TSPN group (P < 0.05). The times across the platform were less in the vehicle group than that in the TSPN group (P < 0.05). In comparison with the vehicle group, the number of the NeuN+ cells in the CA1 subfield and DCX+ cells in the SGZ of the TSPN group were significantly increased (P < 0.01); Moreover, the result of immunoblotting demonstrated that the protein level of DCX in the CA1 subfield of hippocampus of the TSPN group was significantly higher than that in the vehicle group (P < 0.01). Conclusion: TSPN could improve the learning and memory of global cerebral ischemia rats and its mechanism may be related to the promotion of hippocampus neurogenesis.

Neuroprotective effect of ticagrelor against global cerebral ischemia/reperfusion injury in rats / 中国药理学通报

Aim: To research the neuroprotective effect of ticagrelor against global cerebral ischemia/reperfusion injury in rats. Methods: Fifty adult male Wistar rats were randomly divided into five groups; sham-operation, vehicle, ticagrelor of 3 doses (37.5, 75, 150 mg · kg-1, ig). The global cerebral ischemia was established with four-vessel occlusion. Apoplexy index and neurological symptoms were detected after reperfusion injury 2 h, 24 h, 48 h. HE staining and Nissl staining were applied to assess the neuronal injury after global cerebral ischemia/reperfusion injury in CA1 region of hippocampus. Platelet aggregation induced by ADP in rats was measured with turbidimetric method. Four items of coagulation were detected by automatic coagulation analyzer. Results: Compared with vehicle, the low, medium and high doses of ticagrelor reduced the apoplexy index at 24h (P <0. 05), 48 h(P < 0. 01), and significantly reduced the neurological symptom at 48 h (P < 0. 01), and could significantly reduce platelet aggregation of rats (P < 0. 01), the number of neurons in CA1 region of hippocampus was larger (P < 0. 01), and it also significantly protected the neurons in both number and morphology. Conclusions: The ticagrelor possesses neuroprotective effect against global cerebral ischemia/reperfusion injury in rats, and it may be as a drug of neuroprotective agent in further study.

Pretreatment of Populus tomentiglandulosa protects hippocampal CA1 pyramidal neurons from ischemia-reperfusion injury in gerbils via increasing SODs expressions and maintaining BDNF and IGF-I expressions / 中国天然药物

To examine the effects of Populus tomentiglandulosa (PT) extract on the expressions of antioxidant enzymes and neurotrophic factors in the cornu ammonis 1 (CA1) region of the hippocampus at 5 min after inducing transient global cerebral ischemia (TGCI) in gerbils, TGCI was induced by occlusion of common carotid arteries for 5 min. Before ischemic surgery, 200 mg·kg PT extract was orally administrated once daily for 7 d. We performed neuronal nuclear antigen immunohistochemistry and Fluoro-Jade B staining. Furthermore, we determined in situ production of superoxide anion radical, expression levels of SOD1 and SOD2 as antioxidant enzymes and brain-derived neurotrophic factor (BDNF) and insulin-like growth factor I (IGF-I) as neurotrophic factors. Pretreatment with 200 mg·kg PT extract prevented neuronal death (loss). Furthermore, pretreatment with 200 mg·kg PT extract significantly inhibited the production of superoxide anion radical, increased expressions of SODs and maintained expressions of BDNF and IGF-I. Such increased expressions of SODs were maintained in the neurons after IRI. In summary, pretreated PT extract can significantly increase levels of SODs and protect the neurons against TGCI, suggesting that PT can be a useful natural agent to protect against TGCI.

Effects of total saponins of panax notoginseng on depressive behavior and hippocampal nerve regen-eration in rats with following global cerebral ischemia depression / 中华行为医学与脑科学杂志

Objective To explore the effect of the total saponins of panax notoginseng ( TSPN) on depression-like behavior following global cerebral ischemia depression in rats and its mechanism. Method-s Using four-vessel occlusion method to build the global cerebral ischemia model,then the cerebral ischemi-a rats were given solitary breeding with chronic unpredictable mild stress ( CUMS) to prepare depression model. Seventy rats were divided into sham group (n=10),model group ( n=20),PSD group ( n=20) and TSPN group (n=20). The rats in the TSPN group were administered TSPN intraperitoneally 30 min post-brain ischemia. The dose of TSPN (75mg/kg) was suspended in 0. 9% saline 10g/L,once per day for 30 days after reperfusion. While rats in the vehicle group and PSD group was treated with equal volume of 0. 9% saline,one injection per day until the rats were sacrificed at 30 days after brain ischemia. The BrdU,dou-blecortin (DCX) expression in the hippocampus was assessed by immunohistochemistry. Results In com-parison with the model group,the sucrose preference percentage in the PSD group was significantly lower ((46. 2±9. 2)%,(61. 2±7. 6)%;t=3. 18,P<0. 05),then the PSD rats were administered TSPN intraperito-neally,the sucrose preference percentage increased significantly ((62. 4±3. 4)%,(46. 2±9. 2)%;t=3. 43, P<0. 05). During the forced swimming test,the immobility time of PSD group was significantly increased compared with the model group ((119. 4±9. 7)s,(88. 0±15. 6)s ;t=4. 30,P<0. 01),while after PSD rats administering TSPN intraperitoneally,the immobility time was shorten remarkably ((97. 4±6. 7)s,(119. 4± 9. 7)s;t=3. 01,P<0. 05). Compared with the Model group( BrdU+:( 12. 6± 2. 2)/mm2,DCX+:( 38. 6± 4. 2)/mm2),the number of BrdU+ and DCX+ cells in the SGZ of hippocampus in PSD group decreased (BrdU+:(8. 8±1. 5)/mm2,DCX+:(27. 2±2. 8)/mm2;t=3. 25,4. 29,both P<0. 01). And compared with PSD group,the number of BrdU+ and DCX+ cells in the SGZ of hippocampus in TSPN group increased sig-nificantly (BrdU+:(14. 8±2. 8)/mm2,DCX+:(37. 0±3. 3)/mm2;t=4. 68,3. 69,both P<0. 05). Conclu-sion TSPN can improve the depression-like behavior of rats following global cerebral ischemia,which may be related with promoting hippocampal nerve regeneration.

Effect of liver X receptor activation on hippocampal neural stem cell proliferation and cognitive function in global cerebral ischemia/reperfusion mice / 中国药理学通报

Aim To investigate the effect of liver X receptor (LXR) activation on the proliferation of hippocampal neural stem cells in global cerebral ischemia/reperfusion (I/R) mice,and its mechanisms.Methods A total of 75 C57BL/6 mice were randomly divided into three groups,namely the sham operation group,the cerebral I/R group and the cerebral I/R with TO901317 treatment (I/R + TO90) group.The I/R mouse model was induced via the bilateral common carotid artery occlusion.HE staining was used to detect the pathological changes in hippocampal CA1 region.Immunohistochemistry was executed to detect hippocampus DCX + cells.Immunofluorescence of BrdU was implemented to detect the proliferation neural stem cell.Morris water maze test was used to assess spatial learning and memory in mice.Western blot was used to detect the expression of hippocampus LXRα,LXRβ,ABCA1,p-ERK1/2,t-ERK1/2,p-CREB,t-CREB,BDNF.Results LXR activation improved cognitive recovery(P ＜0.01),and induced the proliferation of neural stem cells (P ＜ 0.01) in I/R mice.The expressions of hippocampal ABCA1,p-ERK1/2,p-CREB,BDNF in I/R + TO90 group mice also increased (P ＜ 0.01).Conclusions LXR activation can induce the proliferation of hippocampal neural stem cells and facilitate cognitive recovery following global cerebral I/R in mice,which may be related to the activation of hippocampal ERK1/2-CREB-BDNF pathway and then promoting endogenous neurogenesis in the hippocampus DG region of I/R mice.

Cysteinyl leukotriene receptor antagonist alleviates global cerebral ischemia/reperfusion injury in gerbils through down?regulating autophagy / 中国实验动物学报

Objective Cysteinyl leukotrienes are potent inflammatory mediators. Their actions are mediated by specific receptors,the CysLT receptors(CysLT1R and CysLT2R),which have been cloned and characterized. In this stud-y,we investigated the protective effects of the CysLTR antagonist Pranlukast and HAMI 3379 on global cerebral ischemia/reperfusion(CI/R)injury in gerbils and its underlying mechanisms. Methods The gerbil model of CI/R was established by bilateral common carotid artery occlusion for 10 min followed by 24 h reperfusion. Then the animals were equally ran-domized into four groups: sham, model, Pranlukast(0.1 mg/kg)and HAMI 3379(0.1 mg/kg)groups. The later two groups were treated with intraperitoneal injection of Pranlukast and HAMI 3379,respectively,once daily for 4 days before carotid artery occlusion,while the former two groups with saline only,all at 10 mL/kg. After 24 h reperfusion,neurologi-cal deficit scores were observed and the behavioral dysfunction was assessed. The neuron morphology of cerebral cortex and CA1 subregion of hippocampus were observed in brain sections stained with cresyl violet. The expression of autophagy-relat-ed proteins beclin-1 and LC3 in the homogenate of cerebral cortex and hippocampus were determined using western blotting analysis. The ultrastructure of autophagosomes in the CA1 subregion of hippocampus was observed by electron microscopy. Results Compared with the model group, Pranlukast and HAMI 3379 attenuated neurological deficits, improved the be-havioral dysfunction,inhibited the neuron injury and loss, decreased the expression of autophagy-related protein beclin-1 and LC3 and the number of autophagosomes. Conclusions cysteinyl Leukotriene receptor antagonist Pranlukast and HAMI 3379 can alleviate global cerebral ischemia/reperfusion injury in gerbils. The protective effects of Pranlukast and HAMI 3379 appear to be associated with the inhibition of autophagy.

Effect of total saponins of Panax notoginseng on expression of GFAP in hippocampus and brain water content in rats subjected global cerebral ischemia injury / 中草药

Objective To explore the effect of the total saponins of Panax notoginseng (TSPN) on the expression of GFAP in hippocampus and brain water content in rats subjected global cerebral ischemia injury. Methods Using four-vessel occlusion method built the global cerebral ischemia model. Rats were divided into Sham group, vehicle group, and TSPN group. The rats in the TSPN group were administered TSPN intraperitoneally 30 min post-brain ischemia. The dose of TSPN (75 mg/kg) was suspended in 0.9% saline, once per day for days 1, 3, 7, and 14 after reperfusion. While rats in the vehicle group was treated with equal volume of 0.9% saline, one injection per day until the rats were sacrificed at either days 1, 3, 7, and 14 after brain ischemia. The brain water contentwas detected by dry-wet technique and GFAP expression in the dentate subgranular zone (SGZ) was assessed by immunohistochemistry. Moreover, immunofluorescence was applied to detect the GFAP/DCX in the SGZ, and western-blot was adopted to test the protein level of GFAP. Results The brain water content in the TSPN group was significantly lower than the vehicle group (P < 0.05); There was statistical difference in the GFAP+ cells density in SGZ at the 3th, 7th, 14th day in two groups (P < 0.05). Furthermore, compared with the vehicle group, the ratio of the GFAP/DCX to DCX in the SGZ at 7th, 14th d of TSPN group was significantly different (P < 0.05), and the protein level of GFAP on days 3, 7, 14 in the TSPN group was higher (P < 0.05). Conclusion TSPN could play a neuroprotective effect through promoting gliosis, neuroregeneration in the SGZ, and alleviating brain water content of rats following global cerebral ischemia.

Effects of High Thoracic Epidural Anesthesia on Cerebral Blood Flow and Hippocampal Apoptosis during Global Cerebral Ischemia and Reperfusion in Rats / 现代生物医学进展

Objective:To investigate the effects of high thoracic epidural anesthesia (HTEA) on the cerebral blood flow (CBF) and hippocampal apoptosis-related proteins Bcl-2 and Bax during global cerebral ischemia and reperfusion (GCI) in rats.Methods:Fifteen-minute global ischemia was established by 4-vessel occlusion and epidural catheterization was performed through T4-5 intervertebral spaces in adult male Wistar rats.According to the different drugs infused into the epidural space,the rats were randomly divided into four groups:Sham group (0.9 ％ NaC1),Sham-HTEA group (0.25 ％ bupivacaine),GCI group (global cerebral ischemia,0.9 ％ NaC1) and HTEA group (global cerebral ischemia,0.25 ％ bupivacaine).And 0.25 ％bupivacaine or 0.9 ％ saline (20 μL·h-1) was infused continuously to the thoracic epidural space from 15 minutes before ischemia to 24 hours after reperfusion.Mean arterial pressure (MAP),heart rate (HR) and cerebral blood flow (CBF) were determined until 2 hours after reperfusion,and the hippocampal Bcl-2 and Bax proteins at 24 hours after reperfusion were examined by Western-blot.Results:Compared with the GCI group,HTEA group has no significant difference on MAP and HR during ischemia and 2 hours after reperfusion,andcompared with the Sham group,MAP in GCI group increased in ischemia 0 min and decreased in reperfusion 0 min.The CBF in HTEA group was significantly lower than that in GCI group (123.1％± 35.2％ vs 177.5％± 32.4％,P＜0.01) in reperfusion 10 min,and higher than that in GCI group during the hypoperfusion of 60 to 120 minutes after reperfusion (P＜0.05),and the ratio of Bax/Bcl-2 in hippocampus was significantly decreased in HTEA group 24 hours after reperfusion (P＜0.01).Conclusions:Continuous HTEA infusion of 0.25 ％ bupivacaine 20 μL ·h-1 could maintain the hemodynamic stability,and improve the CBF of hypoperfusion period in rats,as well as reduce the ratio of Bax/Bcl-2 at 24 hours after reperfusion.

Pre-treated Populus tomentiglandulosa extract inhibits neuronal loss and alleviates gliosis in the gerbil hippocampal CA1 area induced by transient global cerebral ischemia / 대한해부학회지

The genus Populus (poplar) belonging to the Salicaceae family has been used in traditional medicine, and its several species show various pharmacological properties including antioxidant and anti-inflammatory effects. No study regarding protective effects of Populus species against cerebral ischemia has been reported. Therefore, in the present study, we examined neuroprotective effects of ethanol extract from Populus tomentiglandulosa (Korea poplar) in the hippocampal cornu ammonis (CA1) area of gerbils subjected to 5 minutes of transient global cerebral ischemia. Pretreatment with 200 mg/kg of P. tomentiglandulosa extract effectively protected CA1 pyramidal neurons from transient global cerebral ischemia. In addition, glial fibrillary acidic protein immunoreactive astrocytes and ionized calcium binding adapter molecule 1 immunoreactive microglia were significantly diminished in the ischemic CA1 area by pretreatment with 200 mg/kg of P. tomentiglandulosa extract. Briefly, our results indicate that pretreatment with P. tomentiglandulosa extract protects neurons from transient cerebral ischemic injury and diminish cerebral ischemia-induced reactive gliosis in ischemic CA1 area. Based on these results, we suggest that P. tomentiglandulosa can be used as a potential candidate for prevention of ischemic injury.

Inhibition and machanisms of total saponins from Panax notoginseng on apoptosis of hippocampal CA1 subfield neurons of rats following global cerebral ischemia / 中草药

Objective: To explore whether total saponins of Panax notoginseng (TSPN) can protect hippocampal CA1 subfield neurons against apoptosis following global cerebral ischemia via up-regulating the Bcl-2/Bax ratio and preventing Caspase-3 activation. Methods: Using four-vessel occlusion method to build the global cerebral ischemia model and the ischemia time was 30 min. All rats were divided into Sham group, vehicle group, and different doses (25, 50, 75, and 100 mg/kg) of TSPN groups. The rats in TSPN groups were ip administered with TSPN. The dose of TSPN was suspended in 0.9% saline (10 g/L), while rats in vehicle group were treated with equal volume of 0.9% saline, one injection per day. Compared the survival rate and hippocampal CA1 subfield neuronal density by Nissl staining after reperfusion of 14 d to make sure the best dose of TSPN for neuroprotection. Then to evaluate the neurological score and investigate the expression level of the Caspase-3, Bcl-2, and Bax in the hippocampus CA1 region at days 1, 3, 7, and 14 post-ischemia by immunohistochemistry; In addition, the Western-blotting was adopted to test the protein level of these three proteins. Results: The survival rate of the rats in 75 mg/kg TSPN groups was 100%, and its neuronal density was significantly higher than that in vehicle group and other doses of TSPN groups (P < 0.05); The neurological score in TSPN group was significantly less than that in vehicle group (P < 0.01); The Caspase-3 neuronal density in the CA1 subfield of TSPN group on days 7 and 14 was significantly less than that in vehicle group (P < 0.001); The statistical meaning existed about the protein level of Caspase-3 with molecular weight of 20 000 on days 3, 7, and 14 and 17 000 on days 7 and 14 in two groups (P < 0.001). The neuronal density of Bcl-2 cells in the CA1 subfield and Bcl-2 protein level in the hippocampus of TSPN group at days 7 and 14 was significantly higher than that in vehicle group (P < 0.001); Besides, the Bax neuronal density at days 7 and 14 was significantly lower than that in vehicle group (P < 0.001); And its protein level of the hippocampus was less than that in vehicle group at days 3, 7 and 14 (P < 0.001). The results of ratio of Bcl-2/Bax from not only the neuronal density but also the protein expression demonstrated that the Bcl-2/Bax ratio in TSPN group was significantly higher than that in vehicle groups on days 7 and 14 (P < 0.001). Conclusion: TSPN can protect the hippocampal CA1 subfield neurons against apoptosis following global cerebral ischemia in adult rats via up-regulating the Bcl-2/Bax ratio and preventing Caspase-3 activation.

Effect of total saponins of Panax notoginseng on neuroregeneration in subventricle zone of rats with global cerebral ischemia / 中草药

Objective: To explore the effect of total saponins of Panax notoginseng (TSPN) on the neuroregeneration in subventricle zone (SVZ) in rats with global cerebral ischemia. Methods: Using four-vessel occlusion method to build the global cerebral ischemia model. Rats were divided into Sham group, vehicle group, and TSPN group. The rats in TSPN group were ip administered with TSPN 30 min post-brain ischemia. The dose of TSPN (75 mg/kg) was suspended in 0.9% saline (10 g/L), once per day for 1, 3, 7, 14 days after reperfusion. While rats in the vehicle group were treated with equal volume of 0.9% saline, one injection per day until the rats were sacrificed at either 1, 3, 7, and 14 days after brain ischemia. The BrdU and Doublecortin (DCX) expression in SVZ was assessed by immunohistochemistry and applying the immunofluorescence double-labelling to detect the BrdU/DCX, DCX/Ki67, and GFAP/DCX in SVZ. Results: In comparison with the vehicle group, the number of BrdU+ cells in SVZ of TSPN group was significantly higher on days 7 and 14 (P < 0.01, 0.001); Statistical meaning existed in two groups on days 7 and 14 about the mean optical density of DCX+ cells in SVZ (P < 0.01, 0.001). In comparison with the vehicle group, the number of the BrdU-labeled cells co-expressing DCX in the SVZ on day 14t of TSPN group was significantly different (P < 0.01, 0.001). There was statistical meaning in comparison of the number of colocalization of DCX with Ki67 on days 7 and 14 in SVZ between the TSPN group and vehicle group (P < 0.01, 0.001). The ratio of GFAP/DCX to DCX in SVZ of two groups were statistically different on days 2, 7, and 14 (P < 0.05, 0.001). Conclusion: TSPN could promote the neuroregeneration, drive the proliferation and differentiation of neural progenitor cells, and enhance the differentiation of gliosis into newborn immature neurons in SVZ of rats with global cerebral ischemia.

Protective effect of hydrogen gas on neurons in rat hippocampus CA1 region during global cerebral ischemia/reperfusion injury / 实用医学杂志

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.

Effects of treadmill running pretreatment on the expression of CyclinA and CyclinE protein in hippo-campus of rats after global cerebral ischemia and reperfusion / 中华行为医学与脑科学杂志

Objective To investigate the effect of treadmill running pretreatment on the expression of CyclinA and CyclinE protein in hippocampus of rats after global cerebral ischemia and reperfusion.Meth-ods 60 healthy male wister rats were randomly divided into control group, model group and experiment group.Global cerebral ischemia reperfusion model was generated by improved four-vessel occlusion as de-scribed according to the description of Pulsinelli's method.Rats in the experiment group were performed treadmill running for 2 weeks before injury.The water maze test was performed at 24 h and 48 h respectively after injury to determine the spatial memory ability of rats.Morphological changes of hippocampus were ob-served by HE staining ( hematoxylin-eosin staining) at 3 h,6 h,24 h,48 h after injury and the expression of CyclinA and CyclinE were detected by immunohistochemical staining.Results Compared with control group,the survival rate of neurons in the model group was significantly decreased at each time point.Morris water maze test showed that the escaping latency of rats in the model group was significantly prolonged( 24 h (24.35±3.99)s,48 h(33.08±5.85)s),and the frequency of crossing the platform was decreased(24 h(6.80 ±0.79),48 h(4.00±0.67)).The expression of CyclinA was increased significantly in the model group ((8.40±0.52)/high view,(11.70±1.06)/high view,(15.50±0.53)/high view,(22.40±0.52)/high view) as well as the expression of CyclinE((20.30±0.48)/high view,(15.20±0.63)/high view,(10.00± 0.82)/high view,(7.70±0.68)/high view) (P<0.05).Compared with model group,the survival rate of neurons in the model group was significantly increased at each time point.Morris water maze test showed that the escaping latency of rats in the experiment group was significantly shorten(24 h(13.21±2.73) s,48 h (24.20±4.66)s),and the frequency of crossing the platform was increased(24 h(9.70±0.95),48 h(6.30± 1.16)).The expression of CyclinA was significantly increased in the model group((10.60±0.84)/high view),(16.70± 0.68)/high view),(24.50±0.53)/high view),(36.20±1.40)/high view) as well as the expression of CyclinE((31.60 ±0.70)/high view),(24.50±0.70)/high view),(16.80±0.63)/high view),(9.10±0.74)/high view) (P<0.05).Con-clusion The treadmill running pretreatment improves the function of spatial memory after global cerebral ischemia and reperfusion,potenlially mediated by regulating the expression for cell cycle proteins,which have a protective effect on cerebral brain tissue.

Effect of Chinese Patent Medicine Naodesheng against Repeated Transient Global Cerebral Ischemia in Mice / 中草药·英文版

Objective: To investigate the therapeutic effect and possible mechanisms of Chinese ptent medicine Naodesheng (NDS) on repeated transient global cerebral ischemia (GCI) in mice. Methods: The repeated transient GCI mice were induced by bilateral carotid arteries ligation, and were randomly divided into model group, Sham group without arteries ligation, NDS groups (1.25 and 2.5 g/kg) and positive control (vinpocetine 3.1 mg/kg, VP) group. After oral administration once daily for successive 7 d, the transient GCI was induced. The degree of neurological deficit, histological changes, and neurons loss in the hippocampus were evaluated. In order to investigate the possible mechanisms, the oxidative stress and inflammatory factor were measured after 24 h of GCI. Comparison among multiple groups was performed with one-way analysis of variance (ANOVA). Results: NDS could significantly alleviate the neurological function impairment, histological injury, and neurons loss, increase the superoxide dismutase (SOD) activity, decrease the content of malondialdehyde (MDA), and reduce inflammatory factor in the ischemic brain tissue. Conclusion: NDS could significantly reduce brain injury induced by global ischemia, and its mechanism is closely associated with anti-oxidation and anti-inflammation.

Fu-Yuan-Zai-Zao capsule improves learning and memory ability through inhibiting oxidative stress in global brain ischemic mice / 中国比较医学杂志

Objective To investigate the effects of Fu-Yuan-Zai-Zao capsule , a novel compound drug of traditional Chinese medicine , on learning and memory ability and its mechanism related to oxidative stress induced by global brain ischemia .Methods The mouse model of global brain ischemia was established by bilateral common carotid arteries occlusion and reperfusion .The learning and memory ability was measured by Morris water maze and step down tests.Nissl staining was used to detect the pathological changes in the hippocampal neurons .The activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) were evaluated by xanthinoxidase assay and thiobarbituric acid method , respectively .Results The global brain ischemia and reperfusion induced an impairment of learning and memory function, a decrease in the number of neurons in the hippocampal CA 1 region, a decline in SOD activity and an increase in MDA content in the cerebral cortex of mice .Intragastrical administration of Fu-Yuan-Zai-Zao capsule for 14 d after brain ischemic surgery significantly improved the learning and memory impairment , increased the number of neurons in the hippocampal CA1 region, elevated SOD activity and reduced MDA content in the cerebral cortex .Conclusions Fu-Yuan-Zai-Zao capsule ameliorates the learning and memory impairment through inhibiting oxidative stress induced by global brain ischemia in mice .The results suggest that Fu-Yuan-Zai-Zao capsule may have future application in the treatment of ischemic cerebrovascular diseases .

Neuroprotection of rifampicin in global cerebral ischemia via inhibiting microglial activation / 中国免疫学杂志

Objective:To investigate the protective effect of rifampicin in a rat model of global cerebral ischemia /reperfusion ( GCIR) and discuss the influence of rifampicin on microglial activation.Methods:The GCIR rat model was induced via the bilateral occlusion of the common carotid arteries and systemic hypotension.Forty-two male SD (Sprague-Dawley) rats were randomly assigned to three groups:sham group ,I/R and I/R+FRP treated group.The rats in I/R+RFP group were treated with rifampicin 20 mg/kg by intra-peritoneal injection 30 min after reperfusion , while the other groups were treated with normal saline.Morris water maze test was performed for neurobehavioral test ,HE staining was detected for pathomorphology changes of neurons in CA 1 region.Microglia was im-munohistochemically stained in CA 1 region using ionized calcium adaptive molecular 1 ( IBA-1) as the marker.The protein levels of IL-1β,IL-6 and TNF-αin the hippocampal tissues of rats were also measured by enzyme-linked immunosorbent assay.Results:Rifampin improved the behavior ,shorten the escape latency of rats following GCIR obviously ( P<0.05 ) and reduced the neuron damage in hipp-ocampal CA1 region of rats after GCIR (P<0.05).Additionally,in I/R+FRP treated group the activation of microglia also showed a significantly inhibited compared with I/R group(P<0.05).Futhermore,we also found the expression of IL-1β,IL-6 and TNF-αin hipp-ocampal reduced obviously in I/R+FRP group ( P<0.05 ).Conclusion: Rifampin have obvious protective effect in the rat model of GCIR.The underlying mechanism may be associated with inhibition the activation of microglia ,reduction the expression of IL-1β,IL-6 and TNF-αand suppression the inflammatory response finally.