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Objective:To observe the changes of inflammatory damage in the brain of rats after focal cerebral ischemia-reperfusion, and explore the effect of the initiation of IκB kinases β (IKKβ), which is the key protein of activating nuclear factor (NF)-kappa B signaling pathway in inflammatory response, and the mechanism of electroacupuncture inhibiting inflammatory damage. Methods:A total of 240 male Sprague-Dawley rats were randomly divided into sham group, ischemia-reperfusion group, electroacupuncture group, IKKβ silencing group, IKKβ overexpression group and IKKβ overexpression + electroacupuncture group, each group was further divided into six hours, twelve hours, 24 hours, 48 hours and 72 hours subgroups. The right middle cerebral artery occlusion reperfusion model was established by modified thread embolization. The IKKβ gene was intervened by gene silencing and gene overexpression technology. Results:Compared with the model group, the neurological function score increased (P < 0.05), the cerebral infarction volume decreased (P < 0.05), the activation of NF-κB p65 was inhibited, and the content of proinflammatory factors decreased (P < 0.05) in IKKβ silencing group. Compared with IKKβ silencing group, the above results were significantly worse in IKKβ overexpression group (P < 0.05), and microglia in cerebral ischemic cortex were significantly activated. The activation of microglia and activation of IKKβ were significantly inhibited in IKKβ overexpression + electroacupuncture group. Conclusion:IKKβ gene silencing could inhibit the inflammatory response of cerebral ischemic cortex mediated by NF-κB signaling pathway, and over-expression of IKKβ could lead to severe inflammatory damage in ischemic cortex. Electroacupuncture could inhibit the inflammatory damage after focal cerebral ischemia-reperfusion by regulating the activity of IKKβ.
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Objective To explore the effect of sufentanil postconditioning on the focal cerebral is-chemia reperfusion injury in diabetic rats. Methods An intraperitoneal injection of 50 mg/kg streptozotocin was used to induce diabetes in rats. Meanwhile,the diabetes mellitus model was confirmed by the blood glu-cose level over 16. 7 mmol/L. The diabetes mellitus male SD rats,weighting 250-300 g,were randomly divid-ed into 3 groups:sufentanil postconditioning diabetic group (SP-DM),ischemia reperfusion diabetic group (IR-DM),sham operation diabetic group(sham-DM),with 12 in each group. The non-diabetic rats were randomly divided into 3 groups:sufentanil postconditioning non-diabetic group(SP-NDM), ischemia reperfu-sion non-diabetic group(IR-NDM),sham operation non-diabetic group(sham-NDM),with 12 in each group. All rats in the IR-NDM/DM group and SP-NDM/DM group were exposed to the right middle cerebral artery occlusion for 90 minutes followed by 24 hours reperfusion. The sufentanil 1 μg/kg were injected into the rats in SP-NDM/DM group via tail vein at 5 minutes before reperfusion. Normal saline was injected into the rats in sham-NDM/DM group and IR-NDM/DM group at 5 minutes before reperfusion. At 24 hours after reperfu- sion,the neurological deficit scores( NDS) were assessed,then all the rats were sacrificed. Infarct volume, which was determined by 2,3,5-triph-enyltetrazolium ( TTC) staining,and water content of right hemisphere for brain edema were also measured. Results All rats showed neurological deficit,brain infarction and brain edema after focal cerebral ischemia reperfusion. (1) At 24 hours after reperfusion,the neurological deficit score in IR-DM group(3. 4±0. 4) was significantly higher than that in the IR-NDM group(2. 8± 0. 5) ( t=2. 313,P<0. 05),there was no significant difference in neurological deficit score between the SP-DM group (3. 3±0. 4) and the IR-DM group(t=1. 546,P>0. 05). (2) At 24 hours after reperfusion,the infarct volume in IR-DM group((58. 3±2. 1)%) was significantly higher than that in the IR-NDM group((32. 1±2. 6)%) (t=2. 912, P<0. 05), there was no significant difference in infarct volume between the SP-DM group ((56. 9±2. 1)%) and the IR-DM group(( 58. 3 ± 2. 1)%) ( t=1. 633,P>0. 05). ( 3) At 24 hours after reperfusion,the water content of the right hemisphere in IR-DM group(( 89. 3± 3. 5)%) was significantly higher than that in the IR-NDM group((82. 6±3. 9)%)(t=2. 218,P<0. 05),there was no significant differ-ence in water content of the right hemisphere between the SP-DM group(( 87. 5±3. 4)%) and the IR-DM group(t=1. 730,P>0. 05). Conclusion Sufentanil postconditioning loses neuroprotection against focal cer-ebral ischemia reperfusion injury in diabetic rats.
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Aim To investigate the effects of isoflu-rane on angiogenesis in rats with cerebral ischemia/reperfusion and the possible mechanism. Methods Forty healthy adult male Sprague-Dawley rats were randomly divided into sham operation group (Sham group) , ischemia-reperfusion group (I/R group) , isoflurane post-treatment group (ISO group) and isoflurane post-treatment + Smad3 specific inhibitor SIS3 HC1 group (ISO + SIS3 group). Rat middle cerebral artery occlusion model (MCAO) was established by suture method. After 24 h, Zea-Longa method was used to evaluate the neurological deficit of rats. HE staining was used to evaluate the pathological damage of brain tissues. Nissl staining was used to evaluate the surviving neurons in ischemic brain tissues. TUNEL staining was employed to assess the apoptosis of brain tissues. Immunofluorescence was applied to evaluate the expression levels of VEGF and CD34. Western blot analysis was used to detect the expression levels of p-Smad3, Smad3 , VEGF and CD34. Results Isoflurane significantly reduced the neurobehavioral score of rats, reduced the pathological damage of brain tissues, increased the number of normal neurons in the ischemic brain tissues, reduced the apoptotic cells in injured brain tissues, and enhanced the expression levels of p-Smad3, VEGF and CD34. Smad3 inhibitor re-versed the brain protective effect of isoflurane, aggravated cerebral ischemia-reperfusion injury, and inhibited the protein expression levels of p-Smd3 , VEGF and CD34. Conclusions Isoflurane can improve cerebral ischemia/reperfusion injury in rats, and its protective mechanism is related to activation of Smad signaling pathway, promotion of VEGF and CD34 protein expression , and promotion of angiogenesis.
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OBJECTIVE: To observe the effect of electroacupuncture (EA) and EA combined with intracerebral injection of vascular endothelial growth factor (VEGF) on endoplasmic reticulum stress (ERS) related proteins and genes as activating transcription factor (ATF 6), inositol requiring enzyme-1 (IRE 1), CCAAT/enhancer binding protein homologous protein (CHOP), X box-binding protein-1 (XBP 1) of cerebral ischemia reperfusion injury (CIRI) rats, so as to study its repair effect for CIRI. METHODS: Forty male SD rats were equally and randomly divided into 5 groups: sham operation, model, EA, VEGF and EA+VEGF groups (n=8). The CIRI model was established by occlusion of the middle cerebral artery (MCAO) with thread embolism method. For rats of the sham operation group, the right common carotid artery was isolated without MCAO. EA (2 Hz/100 Hz, 1-3 mA) was applied to "Baihui" (GV 20), left "Quchi" (LI 11) and left "Zusanli" (ST 36) for 30 min, once a day for 14 days. For rats of the VEGF and EA+VEGF groups, 10 µL VEGF (0.025 µg/µL) was injected into the lateral ventricle 24 h after successful modeling. The rats' neurological function was assessed by using the modified neurological severity score (mNSS), and the histopathological changes of cerebral tissue were observed by Nissl staining method. The expression levels of ERS related proteins and genes ATF 6, IRE 1, XBP 1 and CHOP were determined by western blot (WB) and fluorescent quantitative PCR, separately. RESULTS: After modeling, the level of mNSS was significantly higher in the model group than in the sham operation group (P<0.05), and the number of Nissl bodies was markedly lower in the model group than in the sham operation group (P<0.05). Following the treatment, the mNSS was significantly lower in the EA, VEGF and EA+VEGF groups than in the model group (P<0.05), and the numbers of Nissl bodies were obviously higher in the EA, VEGF and EA+VEGF groups than in the model group (P<0.05), suggesting an improvement of neurological dysfunction and a repair of the injured cerebral tissue after the treatment. The levels of CIRI-induced increase of mNSS and CIRI-induced decrease of the number of Nissl bodies in the EA+VEGF group were respectively remarkably lower or higher than those of the simple EA and simple VEGF groups (P<0.05). WB and PCR showed that the expression levels of ATF 6, IRE 1, XBP1 and CHOP proteins and genes were notably higher in the model group than in the sham operation group (P<0.05), and considerably lower in the EA, VEGF and EA+VEGF groups than in the model group (P<0.05). Comparison among the three treatment groups showed that after the treatment, the expression levels of ATF 6, IRE 1, XBP1 and CHOP proteins and genes were obviously lower in the EA+VEGF group than in the EA and VEGF groups (P<0.05). CONCLUSION: EA and EA plus intracerebral microinjection of VEGF can improve neurological function and promote cerebral tissue repair in CIRI rats, which is associated with their effects in down-regulating the expression of ERS related proteins ATF 6, IRE 1, XBP1 and CHOP. The effect of EA+VEGF is superior to that of simple EA and simple VEGF.
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Objective To investigate the effect of exercise preconditioning on the expression of nerve growth factor(NGF) and its receptor TrkA as well as learning-and-memory abilities in rats suffered from focal cerebral ischemia.Methods Thirty-six male SD rats were randomly divided into sham operation group (Sham-MCAO,n=12),focal cerebral ischemia-reperfusion group (MCAO,n=12) and exercise preconditioning + cerebral ischemia-reperfusion group (EX+MCAO,n=12).Rats in EX+MCAO group were placed in the treadmill device and accepted 4 weeks exercise training.Then method of middle cerebral artery occlusion was applied to prepare transient focal cerebral ischemia reperfusion model.Garcia's method was used to assess the neural function in rats.Western blotting was applied to test the expression of NGF and TrkA protein in the successfully established experimental MCAO rats.Morris water maze experiment was uti lized to test the learning-and-memory abilities of the rats.Results (1) Compared with Sham-MCAO group,the expression of NGF in rats' brain tissue was lower in MCAO group (cerebral ischemia 1h reperfusion 24h) (P＜0.05).The expression of NGF of EX+MCAO group was higher than that of MCAO group,but still lower than that of Sham-MCAO group (P＜0.05).(2)The expression of TrkA in rats' brain tissue was higher in MCAO group compared with Sham-MCAO group (P＜0.05).Compared with MCAO group,the expression of TrkA was even higher in EX+MCAO group (P＜0.05).(3)On the fifth day in the Morris water maze test,the latency of MCAO group was significantly longer than that of Sham-MCAO group((9.36± 1.18)s vs (4.86± 1.52) s,P＜0.05).However,compared with MCAO group,the latency in EX+MCAO group ((6.02± 1.04) s) was shorter,but still longer than Sham-MCAO group (P＜0.05).There was no significant difference among the three groups in the average swimming speed (P＞0.05).Conclusion Exercise preconditioning can up-regulate the expressions of NGF and TrkA protein,which can also improve the learning-and-memory abilities in rats suffered from focal cerebral ischemia reperfusion injury.
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@#Objective To investigate the spatial organization of neurons, blood vessel and astrocytes at different time of reperfusion after focal cerebral ischemia in rats. Methods 24 Sprague-Dawley rats were randomly divided into sham group (n=8), reperfusion 1 day group and reperfusion 2 weeks group. The latter 2 groups were occluded the middle cerebral arteries for an hour and reperfused. All the rats were injected with gelatin ink. The expressions of glial fibrillary acid protein (GFAP) and neuronal nuclear antigen (NeuN) in the brain were observed with immunohistochemistry. Results The vessels located mainly in cortex and nucleus. Most of astrocytes apophysis connected with vessels and neurons. Compared to the sham group, the expression of GFAP increased significantly in ischemic side, and the expression of NeuN decreased 1 day and 2 weeks after ischemia-reperfusion. The vessels decreased in the ischemic side 1 day after cerebral ischemia-reperfusion, and then increased 2 weeks later. Conclusion The organization of neurovascular unit after cerebral ischemia-reperfusion has been observed.
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Objective To explore the effect and mechanism of electroacupuncture on eNOS in mobilizing endothe -lial progenitor cells (EPCs) in rat bone marrow and peripheral blood to promote revascularization in focal cerebral ischemi -a/reperfusion rat.Methods A total of 100 healthy male adult Sprague-Dawley (SD) rats were randomly divided into nor-mal group ( N) , model group ( I/R) , electroacupuncture group ( I/RE) and I/RE plus L-NAME ( A specific antagonist of eNOS) group (I/REL), and were further divided into 1 d, 2 d and 7 d subgroups after reperfusion, 10 rats in each group, in addition to the N group .The rats received filament occlusion of the right middle cerebral artery for 1.5 hours followed by reperfusion .“Baihui” ( GV 20)/“Siguan” ( Hegu LI 4/Taichong LR 3) were selected as acupucture points .Flow cytome-ter was used to detect the percentage of EPCs in bone marrow and peripheral blood .The expression of VEGFR2 mRNA was tested by fluorescence quantitative PCR .Immunohistochemical staining was used to detect VEGFR 2 +cells and to stain the CD34 +microvessels.Results Compared with the I/R group, there was a significant up-regulation of the percentage of EPCs in bone marrow and peripheral blood by electroacupuncture (P<0.01,P<0.05), but decreased by the inhibitor of eNOS (P<0.01).Compared with the I/R group, the VEGFR2 +cells, expression of VEGFR2 mRNA and CD34 +mi-crovessels were significantly increased in the I/RE group ( P<0.01 ) , but decreased in the I/REL group ( P<0.01 ) . Conclusions Electroacupuncture can effectively mobilize EPCs to promote the revascularization in focal cerebral ischemia /reperfusion rat .This effect is attenuated by inhibitor of eNOS , suggesting that the activation of eNOS mediated by electroa-cupuncture may be related to mobilizing EPCs to promote the revascularization .
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Objective To observe the effect of estrogen on BBB permeability,occludin expression after ischemia-reperfusion in rats,and to make a further investigation on the role of estrogen in cerebral ischemia. Methods Ovariectomized rats were randomly divided into sham-operated group,model group,and estrogen pretreatment group. 4 h,24 h,3 d after ischemia-reperfusion were selected as different observation points,and changes of edema,occluding expression,and blood-brain barrier permeability of the 3 points in time were observed. BBB ultra-structure electron microscope observation was made at 24 h and 3 d after ischemia-reperfusion. Changes in cerebral edema were measured by brain water content percentage;protein expressions were measured by Western blot;and BBB permeability was measured by Evans blue as-say. Results Compared with the sham group,brain tissue water content and EB content in model group both increased 4 h after ischemia-reperfusion (P0. 05). 24 h after ischemia-reperfusion,the occludin expression were weaker than that in the sham surgery group with a significant difference (P0. 05). In estrogen group,there was significant difference in occludin protein expression at 24 h and 3 d after ischemia-reperfusion compared with model group at the same time point (P<0. 05). Conclusion BBB ultrastructure disclose TJ was broke and vesicles within EC was increased and astrocyte cell foot process was swelling in MCAO model,it might be the vasogenic brain edema pathological basis for MCAO. In MCAO animal model,with ischemia-reperfusion time increasing,TJ protein occludin expression significantly decreased,it suggests that occludin plays an important role in the regulation of TJ permeability. Estrogen increases has a very close relationship with occludin ex-pression,and it may be one of the mechanisms of protecting BBB integrity and lessening cerebral edema.
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AIM:To investigate the influence of high-mobility group box 1 (HMGB1) on the proliferation of neural stem cells in peri-infarction cortex of focal cerebral ischemia/reperfusion model rats .METHODS: Male SD rats (n=48) were randomly divided into sham group , ischemia/reperfusion (I/R) group, RNA interference group and nega-tive interference group .The rat middle cerebral artery was blocked to establish focal cerebral I /R model ( ischemia for 1 h and reperfusion for 7 d).Lentivirus vector of HMGB1 shRNA was used to suppress the HMGB1 protein expression in the rat brain.The effect of RNA interference was evaluated by the methods of double-immunofluorescence labeling of HMGB 1/GFAP and Western blotting .The proliferation of neural stem cells in the peri-infarction cortex was assessed by double labe-ling of BrdU/nestin.RESULTS: The protein expression of HMGB1 in I/R group was much higher than those in sham group (P<0.05).RNA interference effectively inhibited the HMGB1 expression (P<0.05).Double labeled BrdU/nestin positive cells in I/R group were more than that in sham group (P<0.05).The double labeled BrdU/nestin positive cells were significantly decreased in RNA interference group (P<0.05).CONCLUSION:Focal cerebral ischemia/reperfusion injury promotes the proliferation of neural stem cells in peri-infarction cortex by increasing HMGB 1 protein level .
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Objective To explore the effect of electroacupuncture on CD 34 +VEGFR2 +endothelial progenitor cell (EPC)-derived vessels and stromal cell-derived factor-1α(SDF-1α)/CXCR4, and study its mechanism of promoting an-giogenesis in hippocampus after focal cerebral ischemia /reperfusion .Methods A total of 180 healthy male adult Sprague Dawley (SD) rats were randomly divided into sham operation (sham) group, model (I/R) group, electroacupuncture (I/RE) group, I/RE plus AMD3100 (A specific antagonist of CXCR4) group (I/REA) and AMD3100 (I/RA) group. The rats received filament occlusion of the right middle cerebral artery for 2 hours followed by reperfusion .Electroacupunc-ture was applied to “Baihui” (GV20)/“Siguan” (Hegu LI 4/Taichong LR 3) acupoints for 30 min, once a day.The mR-NA expression of SDF-1αand CXCR4 were detected by reverse transcription-polymerase chain reaction ( RT-PCR) .Double immunofluorescence was used to stain CD 34 +VEGFR2 +EPC-derived vessels.Results Compared with the sham group, the mRNA expressions of SDF-1αand CXCR4 were significantly upregulated in I/R and I/RE group ( P<0.05 ) , but that in I/RE group was more significantly increased than I/R group(P<0.05).In addition, the mRNA expression of SDF-1αand CXCR4 were highly increased on day 1 in the I/REA group than that of I/RE group, but decreased than that of I/RE group on day 7 after reperfusion (P<0.01).CD34 +VEGFR2 +EPCs-derived vessels were obviously increased on 3d and 7d in the I/RE group compared with that of the I/R group, and significantly decreased on 7d in the I/REA group compared with that of the I/RE group ( P<0.01) .Conclusions Electroacupuncture can effectively promote an-giogenesis through upregulating the expression of SDF-1αand CXCR4 in rat ischemic hippocampus after focal cerebral is-chemia/reperfusion.
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OBJECTIVE: To investigate the protective effect of the decoction of tartary buckwheat flavonoids on focal cerebral is-chemia-reperfusion injury of rats. MEHTODS: Fifty male SD rats will be randomly divided into normal group, cerebral ischemia-reperfusion group (model group), high dose of tartary buckwheat flavonoids group, middle dose of tartary buckwheat flavonoids group and low dose of tartary buckwheat flavonoids group, each groups of 10 rats. A rat model of the right middle cerebral artery occlusion/reper-fusion(MCAO) was established by the filament method. After being operated, treatment-group rats will be administered 100,75 and 50 mg · kg-1 of the decoction of tartary buckwheat flavonoids three times a day for 7 consecutive days, after administrated for 7 d, rats in each group will undergo neurobehavioral tests. Expressions of cerebral inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) were measured by SP immunohistochemistry. The optical density value (OD) was measured by imaging analysis, and the percentage of cells with iNOS and eNOS positive expression was analyzed under light microscope. RESULTS: Compared with ischemia-reperfusion group, neurological function score increased in the decoction of tartary buckwheat flavonoids groups. Treatment groups had lower expression level of iNOS but higher expression level of eNOS than those in the model groups (P < 0.01, P < 0.05). The number of neurons of Hippocampal CA1 was increased (P < 0.05). CONCLUSION: Tartary buckwheat flavonoids can improve neurological function and decrease the expression of iNOS and increase the expression of eNOS in cerebral ischemia-reperfusion rats, which may contribute to the protection of neural function.
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Objective To study the changes of SUR1-regulated NCCa-ATP channels in core area during focal cerebral ischemia and reperfusion in rats, and to explore the therapeutic window of focal cerebral ischemia. Methods Adult male Wistar rats were rendered to undergo 120 minutes of the left middle cerebral artery occlusion (MCAO) by the intraluminal thread technique before reperfusion. The core area of the left hemisphere cortex ischemia/reperfusion at different times (reperfusion:R3 h, 6 h, 8 h, 12 h and 24 h) was taken to be tested the level of mRNA and protein expression of sulfonylurea receptor 1 (SUR1) using RT-PCR and Western-blot techniques. SUR1 of the ischemic brain microvascular endothelial cells were observed by immunofluorescence double staining at the peak expressing time point of SUR1. Results We found the up-regulation of SUR1 mRNA and SUR1 protein in ischemic infarcts tissues for R3 h, 6 h, 8 h and 12 h, peaked at R8 h, compared with the sham-operation group ( <0.05) . However, SUR1 expression increased was observed at R12 h by double immunofluorescence in microvascular endothelium. Conclusion SUR1-regulated NCCa-ATP channel may take part in cerebral ischemic damage during focal cerebral ischemia and reperfusion. The expressions of SUR1 mRNA and SUR1 protein were up-regulated in ischemic infarcts tissues. The data suggested that the best time to apply SUR1 inhibitor is within 8-12 hours after ischemia and reperfusion.
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BACKGROUND: Experimental studies have shown that gabapentin can reduce neuronal injury in the setting of cerebral ischemia, but the mechanisms have not yet been clearly determined. This study was conducted to determine whether gabapentin pretreatment altered expression levels of heat shock protein 70 and reduced acute phase neuronal injury in rats subjected to transient focal cerebral ischemia/reperfusion. METHODS: Forty male Sprague-Dawley rats (260-300 g) were randomly assigned to one of four groups (saline-treated, or 0.1, 0.5, or 5 mg/kg gabapentin group). In all animals, focal cerebral ischemia was induced by intraluminal middle cerebral artery occlusion for 1 hour. The animals of the gabapentin groups were pretreated with a single intravenous administration of gabapentin 20 minutes before ischemic insults. The infarct volume, brain edema and motor behavior deficits were analyzed 24 hours after ischemic insult. Caspase-3-reactive cells and cells showing Hsp70 activity were counted in the caudoputamen and fronto-parietal cortex. RESULTS: The infarction ratio was significantly decreased in the 5 mg/kg gabapentin group (P < 0.05) and brain edema ratios were significantly reduced in the 0.1 mg/kg, 0.5 mg/kg, and 5 mg/kg gabapentin groups 24 hours after ischemia/reperfusion injury (P < 0.05). There were more Hsp70-reactive cells in the 5 mg/kg gabapentin group than in the saline group in both the caudoputamen and fronto-parietal cortex (P < 0.05). CONCLUSIONS: These results indicate that gabapentin may have a neuroprotective effect and can reduce early neuronal injury caused by focal cerebral ischemia/reperfusion; this may be mediated by expression of Hsp70. However, gabapentin pretreatment did not prevent caspase-dependent apoptosis.
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Animals , Humans , Male , Rats , Administration, Intravenous , Amines , Apoptosis , Brain , Brain Edema , Brain Injuries , Brain Ischemia , Caspase 3 , Cyclohexanecarboxylic Acids , gamma-Aminobutyric Acid , HSP70 Heat-Shock Proteins , Infarction , Infarction, Middle Cerebral Artery , Neurons , Neuroprotective Agents , Rats, Sprague-DawleyABSTRACT
BACKGROUND: Experimental studies have shown that gabapentin can reduce neuronal injury in the setting of cerebral ischemia, but the mechanisms have not yet been clearly determined. This study was conducted to determine whether gabapentin pretreatment altered expression levels of heat shock protein 70 and reduced acute phase neuronal injury in rats subjected to transient focal cerebral ischemia/reperfusion. METHODS: Forty male Sprague-Dawley rats (260-300 g) were randomly assigned to one of four groups (saline-treated, or 0.1, 0.5, or 5 mg/kg gabapentin group). In all animals, focal cerebral ischemia was induced by intraluminal middle cerebral artery occlusion for 1 hour. The animals of the gabapentin groups were pretreated with a single intravenous administration of gabapentin 20 minutes before ischemic insults. The infarct volume, brain edema and motor behavior deficits were analyzed 24 hours after ischemic insult. Caspase-3-reactive cells and cells showing Hsp70 activity were counted in the caudoputamen and fronto-parietal cortex. RESULTS: The infarction ratio was significantly decreased in the 5 mg/kg gabapentin group (P < 0.05) and brain edema ratios were significantly reduced in the 0.1 mg/kg, 0.5 mg/kg, and 5 mg/kg gabapentin groups 24 hours after ischemia/reperfusion injury (P < 0.05). There were more Hsp70-reactive cells in the 5 mg/kg gabapentin group than in the saline group in both the caudoputamen and fronto-parietal cortex (P < 0.05). CONCLUSIONS: These results indicate that gabapentin may have a neuroprotective effect and can reduce early neuronal injury caused by focal cerebral ischemia/reperfusion; this may be mediated by expression of Hsp70. However, gabapentin pretreatment did not prevent caspase-dependent apoptosis.
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Animals , Humans , Male , Rats , Administration, Intravenous , Amines , Apoptosis , Brain , Brain Edema , Brain Injuries , Brain Ischemia , Caspase 3 , Cyclohexanecarboxylic Acids , gamma-Aminobutyric Acid , HSP70 Heat-Shock Proteins , Infarction , Infarction, Middle Cerebral Artery , Neurons , Neuroprotective Agents , Rats, Sprague-DawleyABSTRACT
Objective To investigate the mechanism by which electro-acupuncture (EA) promotes revascularization in the brain after focal cerebral ischemia and reperfusion.Methods The Sprague-Dawley rat model of focal cerebral ischemia was made by filament occlusion. The rats were randomly divided into a control group, a model group, and an EA group. The model and EA groups were each divided into 5 subgroups receiving reperfusion 1, 3,7, 14 or 21 days after ischemia. EA was given at the bilateral Hegn point (LI 4) in the EA group. The expression of stromal cell-derived factor-1α(SDF-1α) mRNA was detected using a RT-PCR in the 3, 7 and 14 day subgroups.The immunohistochemical method was employed to detect the expression of SDF-1α protein. Results Compared with the control group, expression of SDF-1α protein increased significantly in the model and EA groups. Compared with the model group, the expression of SDF-1α mRNA increased significantly in the 3, 7 and 14 day subgroups.SDF-1α protein expression and microvessel count increased slightly but not significantly in the 1d subgroup, but the increases were significant in the 3, 7, 14 and 21 day subgroups.Conclusions EA may promote angiogenesis in an ischemic area of the cortex by increasing the expression of SDF-1αmRNA and its protein after focal cerebral ischemia and reperfusion.
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@#Objective To explore the effect of cerebellar fastigial nucleus stimulation (FNS) on the expression of Nestin in adult Wistar rat brain after focal cerebral ischemia/reperfusion.MethodsThe animal model of focal cerebral ischemia/reperfusion was made by filament occlusion of the right middle cerebral artery. 180 male Wistar rats were randomly divided into five groups: normal control group (NC group), sham operation control group (SC group), ischemia/reperfusion group (I/R group), ischemia/reperfusion treated with sham FNS group (I/RFs group), and ischemia/reperfusion treated with FNS group (I/RF group), each group contain 1 d, 3 d, 7 d, 14 d, 21 d and 28 d six time points (for each point, n=6). Immunohistochemistry method was used to detect the number of Nestin expression positive cells following various time and interference in lateral cerebral ventriculus and hippocampus in adult Wistar rat brain.ResultsAfter focal cerebral ischemia/reperfusion, the number of Nestin positive cells increased at each time point, reached small peak value in 7th d ( P<0.01). After treated with FNS, the number of Nestin positive cells increased more strikingly at each time point ( P<0.05, P<0.01), reached higher peak value in 7th d ( P<0.01), and maintained at higher level in 14th d. Furthermore, the shape of Nestin positive cells changed significantly.ConclusionFNS can increase the number of Nestin positive cells in some brain regions after focal cerebral ischemia/reperfusion.
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OBJECTIVE:To investigate the protective effect of Guishu blood-activating capsule on cerebral ischemical reperfusion injury of rats.METHODS:The cerebral embolism model rats were established,the rats were randomly divided into model group,nimodipine positive control group,Guishu blood-activating capsule(high,medium and low dosage groups,re?spectively)group and with another sham operation group established.Each group was administered intragastrically with water or the corresponding drugs,the cortexes and hippocampus tissues of the rats were divided into the injured side and the control side,the contents of aspartate(Asp),glutamate(Glu),malonaldehyde(MDA),lactate dehydrogenase(LD),the tumor necrosis factor?(TNF-?)and the activity of glutathione peroxidase(GSH-Px)were determined,the cerebral infarct size was determined by red tetrazoline staining method and the cerebral water content was determined by oven dry process.RE?SULTS:Compared with the model group,in one or several sub-groups of Guishu group,no marked change was noted in the content of Asp while that of the Glu in the injured side of the hippocampus tissues decreased significantly(P
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Aim To study the expression of P-selectin,E-selectin and ICAM-1 and the migration of leukocyte at different time points after focal brain ischemia-reperfusion,and explore the role of cell adhesion molecules in cerebral ischemia-reperfusion damage.Methods The model of focal cerebral ischemia-reperfusion was established with the occluding suture as described by Longa.Sham operation was performed without inserting the suture.Rats were decapitated under anesthesia at 4,8,12,24,and 48 h after ischemia-reperfusion.Brains were immediately removed and samples were handled for following application.Morphological changes of the brain tissue were observed through hematoxylin-eosin staining.The positive expressions of P-selectin,E-selectin,and ICAM-1 were observed and located using immunohistochemistry and immunofluorescent histochemistry technique,respectively.The expressions of P-selectin, E-selectin and ICAM-1 in infracted cortex were measured quantitively with Flow cytometry.The activities of myeloperoxidase in the infracted hemispheres represented the migration of leukocytes were detected through biochemical method.Results The positive cells of P-selectin,E-selectin,and ICAM-1 expressed at the same position of microvessels in the infracted hemisphere were significantly increased after ischemia-reperfusion.Compared with the sham operation group(P-selectin:(4.99?0.08) channel,E-selectin:(4.17?0.13) channel,ICAM-1:(4.17?0.13) channel),the expressions of P-selectin,E-selectin,and ICAM-1 at I/R 4 h((5.46?0.09) channel,(4.60?0.14) channel,(4.56?0.12) channel),I/R 8 h((5.87?0.24) channel,(5.08?0.14) channel,(5.41?0.22) channel),I/R 12 h((6.48?0.18) channel,(5.72?0.18) channel,(5.66?0.16) channel),I/R 24 h((7.16?0.11) channel,(6.09?0.09) channel,(5.61?0.09) channel), and I/R 48 h((5.82?0.28) channel,(5.37?0.25) channel,(5.27?0.16) channel) were increased(P
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Aim To investigate the protective effects and mechanism of aspirin against focal cerebral ischemia-reperfusion in rats. Methods Right middle cerebral artery was occluded by inserting a thread through internal carotid artery for 2 h, and then reperfused for 72 h. 60 mg?kg -1 dose of aspirin was intragastric administrated at 0 h and 6 h after reperfusion. The brain injured area, the mortality, and cerebral edema were estimated. The apoptotic cells of brain tissue were detected by terminal deoxynucleotidyl transferase mediated dUTP-biotin nick-end labeling (TUNEL) method. Bcl-2 and Bax were detected by immunohistochemical staining method. The activity of calcineurin (CaN) in brain tissue was determined by the inorganic phosphorus method. The content of adenosine 5′-triphosphate (ATP) in brain tissue was separated by capillary electrophoresis. Results By using of aspirin 60 mg?kg -1, all indications were dramatically improved. The injured area of brain [from (10.51?1.12)% to (0.94?0.08)%], the cerebral edema of occluded side [from (82.43?2.0)% to (76.29?0.77)%], and the mortality [from 28% to 0%] were dramatically reduced. In brain tissue of occluded side, 60 mg?kg -1 aspirin helped to reduce the number of apoptotic cells from (26.43?2.0) to (17.53?0.44), increase the ratio of Bcl-2/Bax from (0.61?0.05) to (1.01?0.15), inhibit the activity of CaN from (6.03?1.5) to (3.47?0.96), and improve the ATP level from (10.26?1.02) to (25.65?3.45). Conclusion The neuroprotective effects of aspirin on focal cerebral ischemia-reperfusion injury in rats for 72 h might be attributed to its effects by anti-apoptosis, increasing the ratio of Bcl-2/Bax, inhibiting the activity of CaN, and improving the energy metabolism.
ABSTRACT
Aim To investigate the protective effect of zileuton,a 5-lipoxygenase inhibitor,on focal cerebral ischemia-reperfusion injury in rats.Methods The right middle cerebral artery of the rat was occluded by inserting a thread through internal carotid artery for 2 h,and then reperfused for 24 h.Zileuton(10,50 mg?kg~(-1)) was orally administered 2 h before ischemia and 0,5,10 h after reperfusion.After 24 h reperfusion,the content of malondialdehyde(MDA) and nitric oxide(NO),the activities of glutathion peroxidase(GSH-PX),myeloperoxidase(MPO) and nitricoxide synthase(NOS) were measured.Results Compared with vehicle group,the infarct size,content of NO and NOS of the brain were significantly reduced in 10 and 50 mg?kg~(-1) zileuton groups;zileuton 50 mg?kg~(-1) also reduced the content of MDA,increased the activity of GSH-PX,and inhibited the increase of MPO in brain tissue.Conclusion Zileuton possesses the neuroprotective effects on focal cerebral ischemia-reperfusion injury in rats.