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1.
AIM: To explore the survivorship and the mechanism of the intravenous administration of bone marrow stromal stem cells (BMSCs) for treating permanent focal cerebral ischemia in rats. METHODS: After purified, proliferated, and marked with BrdU, the BMSCs were injected intravenously into rats 1 d after focal cerebral ischemia.Modified neurological severity score (mNSS) was evaluated before and following 1, 7, 14 and 28 d after middle cerebral artery occlusion (MCAO). Rats were executed at 1, 7, 14 and 28 d after MCAO. Brain sections were stained with hematoxylin and eosin (HE) for determining the infarct volume. Slides were stained by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) and immunostaining for cleaved caspase-3 method for apoptosis detection and mechanism exploration in situ.RESULTS: mNSS in BMSCs-transplanted group at 14th day and 28th day of MCAO was significantly lower than that in control group(P<0.05). TUNEL-positive cells in the hippocampus and thalamus area of BMSCs-transplanted rats were significantly fewer than those in control rats at 14th day and 28th day of MCAO(P<0.05). Double immunostaining showed that small grafted BMSCs and small endogenous neural cell apoptosis depended on the capase-3 in hippocampus.CONCLUSION: The intravenous administration of BMSCs promotes the recovery of neurological function of rats with focal cerebral ischemia. The therapeutic effect of BMSCs on rats with focal cerebral ischemia may be derived from the reduction of apoptosis and the mobility and migration of endogenous neural stem cells in the ischemic boundary zone.  相似文献   

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AIM: To explore the relationship between apoptosis in the lung tissues and lung ischemia/reperfusion injury, and to observe the effects of human thioredoxin (hTrx) on apoptosis in lung ischemia/reperfusion injury. METHODS: The single lung in situ ischemia/reperfusion animal model was used. Eighty four Wistar rats were randomly divided into control group (control), groups of ischemia for 1 h and reperfusion for different times (IR1h, IR3h, IR5h), and groups of IR+human thioredoxin treatment (IR1h +hTrx, IR3h +hTrx and IR5h +hTrx). Transmission electron microscope (TEM), terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and immunocytochemistry techniques were used to observe apoptosis, apoptosis signal-regulating kinase 1 (ASK1) and expression of Bcl-2 and Bax in various phases of lung ischemia/reperfusion. RESULTS: Cell apoptosis in lung tissues was significantly high, ASK1, Bcl-2 and Bax protein were up-regulated in lung tissues of lung ischemia/reperfusion injury as compared to control (all P<0.01). Compared to IR group, hTrx suppressed apoptosis as well as expression of ASK1 and Bax protein (P<0.01), Bcl-2 protein and the ratio of Bcl-2/Bax were up-regulated in lung tissues (all P<0.05 or P<0.01). There was a significant correlation between the expression of ASK1, Bax protein and cell apoptosis (r=0.775, r=0.814, respectively; all P<0.01). There was a negative correlation between cell apoptosis and Bcl-2/Bax protein (r=-0.275, P<0.05). CONCLUSION: Initiating cell apoptosis by the activation of Bcl-2/Bax system in lung tissues may contribute to the pathogenesis of lung ischemia/reperfusion injury. The protective effects of hTrx include suppressing the expression of ASK1, down-regulating the ratio of Bcl-2/Bax and blocking apoptosis in lung tissues in lung ischemia/ reperfusion injury.  相似文献   

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AIM: To evaluate the influence of maternal limb ischemic preconditioning (LIP) on the apoptosis of fetal hippocampal neurons induced by intrauterine distress-reoxygenation in rats. METHODS: Intrauterine ischemia was induced by clamping the uterine and uterine branch of the ovarian blood vessels with aneurysm clamps for a period of 15 min followed by removal of the clamps to permit reperfusion. Sprague-Dawley (SD) rats (n=12) were randomly divided into 4 groups on the 19th pregnant day: sham (S) group, LIP group, fetal distress (FD) group and LIP+FD group. The cesarean birth occurred on embryonic day 21 to obtain 12 fetal rats alive in each group. The fetal rats were decapitated and the pyramidal cells in CA1 hippocampus were observed under light microscope. The neuronal apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining and the apoptotic rate was calculated. The expression of Bcl-2 and Bax were detected by immunohistochemical method and Western blotting. RESULTS: The rates of neuronal apoptosis in FD group and LIP+FD group were significantly higher than that in S group (P<0.05), while no significant difference was observed between S group and LIP group (P>0.05). The expression of Bcl-2 and Bax in FD group and LIP+FD group was significantly higher than that in S group (P<0.05), while no significant difference was observed between S group and LIP group (P>0.05). The ratio of Bcl-2/Bax was lower in FD group than that in S group. Compared with FD group, the rate of neuronal apoptosis was significantly lower (P<0.05), while the ratio of Bcl-2/Bax was significantly higher (P<0.05) in LIP+FD group. CONCLUSION: Maternal limb ischemic preconditioning attenuates the apoptosis of fetal hippocampal neurons induced by intrauterine distress-reoxygenation in rats, which may be associated with the up-regulation of Bcl-2 expression.  相似文献   

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AIM: To investigate the effects and mechanism of Le Er Mai (LEM) on the apoptosis of hippocampus neuronal cells in the anaphase of cerebral ischemic reperfusion injury in rats.METHODS: A rat model of middle cerebral artery occlusion reperfusion (MCAO) was produced with the intraluminal filament. During reperfusion for 30 d after 2 h of ischemia, the TUNEL staining methods were used to detect apoptosis of hippocampus neuronal cells, and immunohistochemical technique were employed to examine the protein expression of Fas, Bax, caspase-3 and caspase-9 in the hippocampial. The gene expressions of fas, bax, caspase-3 and caspase-9 in hippocampial were examined by RT-PCR. RESULTS: After 2 h ischemia and 30 d reperfusion, compared with sham-operated group, TUNEL-positive staining cells and expression levels of Fas, Bax as well as caspase-3 and caspase-9 obviously increased, and the mRNA expressions of fas, bax, caspase-3 and caspase-9 in hippocampial markedly up-regulated in model group. Compared with model group, LEM at dose of 2.00 g/kg or 0.87 g/kg, and flunarizinum significantly reduced apoptosis and decreased the protein expressions of Fas, Bax, caspase-3 and caspase-9 in hippocampial, and down-regulated the mRNA expressions of fas, bax, caspase-3 and caspase-9 (P<0.05), those action of LEM in 0.87 g/kg dosage group was lower than those in 2.00 g/kg dosage group.CONCLUSION: LEM obviously lower the injury of hippocampial in the anaphase of cerebral ischemia reperfusion through inhibiting the apoptosis of hippocampus neuronal cells. The mechanism of LEM may be related to regulate the expression of signal transduction pathway correlated gene of apoptosis in neuronal cells.  相似文献   

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AIM: To investigate the effects of homocysteine (Hcy) on apoptosis in SV40-transformed aortic rat endothelial cell line and the anti-apoptosis effects of folic acid. METHODS: Cells were treated with different concentrations of Hcy and folic acid, apoptosis was detected by TUNEL and annexin-V/ PI staining methods. Immunohistochemical assay was used to examine the expression of Bax and Bcl-2 in all groups. RESULTS: Both annexin-V/PI staining and TUNEL method showed that Hcy increased endothelial apoptosis in a dose-dependent manner, while folic acid reduced cell apoptosis. Hcy increased expression of Bax and Bcl-2 in endothelial cells, and folic acid decreased it. Bax/Bcl-2 ratio in 0.5 mmol/L Hcy and 5.0 mmol/L Hcy group were upregulated compared with control group (P<0.05 and P<0.01, respectively). Addition of 0.1 mmol/L folic acid decreased Bax/Bcl-2 ratio compared with the corresponding group without folic acid (P<0.05). Correlation analysis showed a strong relation between Bax/Bcl-2 ratio and apoptotic rate (P<0.01). CONCLUSION: Folic acid attenuates the apoptosis induced by Hcy in endothelial cells. Hcy may promote endothelial cell apoptosis via upregulation of Bax /Bcl-2 ratio, which can be partially antagonized by folic acid.  相似文献   

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AIM: To investigate the protective mechanism of extract of Ginkgo biloba (EGB) on apoptosis of hippocampus neuronal cells in type 1 diabetic encephalopathic rats. METHODS: Thirty-six male Sprague-Dauley rats were divided into 3 groups: control group, diabetic group and EGB-treated group. Streptozotocin was injected intraperitoneally to the animals in later two groups to induce diabetes. The rats in EGB-treated group were injected intraperitoneally with EGB, and the same volume of normal saline was injected to the rats in other groups. At the end of the 12th week, the spatial learning and memory abilities of rats in each group were examined by Morris water maze test. Blood glucose and serum insulin concentration were measured. The neuron densities in hippocampus were measured by Image-Pro Plus 6.0 software. The expressions of Bax, Bcl-2, caspase-3 were assayed by Western blotting and immunohistochemistry. RESULTS: Compared to control group, the level of blood glucose (P<0.01), the protein expression of Bax (P<0.01) and caspase-3 (P<0.01) in hippocampus neuronal cells, and the ratio of Bax/Bcl-2 (P<0.01) and the escape latency (P<0.01) in diabetic group, were significantly increased, while the serum insulin concentration (P<0.01), the neuronal density (P<0.05) in CA1,CA2 hippocampal regions and the platform searching score (P<0.01) were significantly deceased. After treated with EGB, the serum insulin concentration (P<0.05), the neuronal density (P<0.05) in CA1,CA2 hippocampal regions and the platform searching score (P<0.01) were significantly increased, while the level of blood glucose (P<0.01), the protein expression of Bax (P<0.05), caspase-3 (P<0.05) in hippocampus neuronal cells, the ratio of Bax/Bcl-2 (P<0.01) and the escape latency (P<0.05) were significantly deceased than those in diabetic group. The protein expression of Bcl-2 in hippocampus neuronal cells did not alter in any experimental rats. CONCLUSION: EGB improves the spatial learning and memory capacity in diabetic rats by decreasing the expression of Bax, Bax/Bcl-2 ratio and down-regulating caspase-3 to reduce neurocyte apoptosis and increase the neuron density in CA1, CA2 hippocampal regions, suggesting that effective regulation of neuron apoptosis associated genes may be one of the mechanisms for EGB to treat diabetic encephalopathy.  相似文献   

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AIM:To investigate the mechanism by which low molecular weight heparin (LMWH) inhibits apoptosis of primary cultured cerebral cortical neurons caused by hypoxia. METHODS:The anti-apoptosis effect of LMWH on primary cultured neurons was observed by methods of the primary culture of cerebral neurons of postnatal rats in free-serum with neurobasal medium supplied with 2% B27 supplement, hypoxic culture of neurons, Hoechst 33342 staining and immunocytochemistry. RESULTS:At concentrations of 250-500 U/L, LMWH reduced apoptosis rate of cerebral cortical neurons induced by hypoxia (P<0.05) and apoptosis rate was lower in LMWH groups than that in BDNF (50 μg/L) group (P<0.05). LMWH (500 U/L) increased Bcl-2 protein expression (P<0.05) and decreased Bax protein expression (P<0.01) in the cerebral cortical neurons induced by hypoxia, the ratio of Bcl-2/Bax was improved (P<0.01). The ratio of Bcl-2/Bax in LMWH (500 U/L) group was higher than that in normal control group, BDNF group and apoptosis positive group (P<0.05). CONCLUSION:LMWH at concentrations of 250-500 U/L is able to prevent cerebral cortical neurons from apoptosis in primary culture under hypoxia. The effect of anti-apoptosis may be related to up-regulation of Bcl-2 protein expression, down-regulation of Bax-2 protein expression, and increase in the ratio of Bcl-2/Bax.  相似文献   

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AIM: To investigate the role of hypoxia-inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) pathway in hyperbaric oxygen (HO) pretreatment in rats with cerebral ischemia-reperfusion (IR) injury. METHODS: Healthy male SD rats (n=32) were randomly divided into control group IR group, HO-IR group and HO-IR-HIF-1α inhibitor group (HO-IR-I group). The IR model was established by middle cerebral artery occlusion. The corresponding blood vessels of the rats in control group were only exposed. The rats in HO-IR group and HO-IR-I group were treated with HO for 4 weeks before the animal modeling. The rats in HO-IR-I group received 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazol (YC-1) by intraperitoneal injection at 4 mg/kg before HO preconditioning every day. At 1 d and 7 d after modeling, the neurological assessment was evaluated.At the end of the 7 th day, after observation, the rats were sacrificed by anesthesia to measure the infarct volume of the brain tissue. The protein levels of HIF-1α, VEGF and apoptosis-related proteins Bax and Bcl-2 were determined by Western blot. The number of apoptotic cells was detected by TUNEL. RESULTS: Compared with control group, the neurological function score was decreased, while the cerebral infarction volume ratio, the protein levels of HIF-1α, VEGF, Bcl-2 and Bax, and the apoptotic cells were increased in IR group, HO-IR group and HO-IR-I group (P<0.05). Compared with IR group, the neurological function score, and the protein levels of HIF-1α,VEGF and Bcl-2 were increased, while the cerebral infarction volume ratio, the protein level of Bax and apoptotic cells were decreased in HO-IR group and HO-IR-I group (P<0.05). Compared with HO-IR group, the neurological function score, and the protein levels of HIF-1α, VEGF and Bcl-2 were decreased, while the cerebral infarction volume ratio, the protein level of Bax and apoptotic cells were increased in HO-IR-I group (P<0.05). CONCLUSION: The mechanism of HO preconditioning attenuating cerebral IR injury may be related to the regulation of apoptosis by inducing HIF-1α/VEGF signaling pathway activation.  相似文献   

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AIM: To study the effects of basic fibroblast growth factor (bFGF) on neuronal apoptosis and fractalkine expression in ischemic penumbra after cerebral ischemia/reperfusion in rats.METHODS: Thirty-six rats were randomly divided into 3 groups: sham operation group, ischemia/reperfusion group and bFGF group. The model of middle cerebral artery occlusion was established by the method of intraluminal filament blockage. The middle cerebral arteries were blocked for 1 h and then reperfused for 24 h. Neurological performances of all rats were scored with Bederson's standard. The brain tissues of the rats were stained and the average infarct volume was calculated. TUNEL method was used to determine the number of apoptotic neurons, and the expression of fractalkine was detected by the method of immunohistochemistry.RESULTS: The score of neurological performances in bFGF group was 2.23±0.59, lower than that in ischemia/reperfusion group (3.18±0.65). The number of apoptotic neurons in bFGF group (13.22±1.35) was lower than that in ischemia/reperfusion group (17.28±1.01, P<0.05), which was the lowest in sham operation group (0.91±0.65). Compared with sham operation group, the expression of fractalkine in ischemia/reperfusion group was decreased. The expression of fractalkine in bFGF group was mainly higher than that in ischemia/reperfusion group (P<0.05).CONCLUSION: Up-regulation of fractalkine may be one of the molecular mechanisms of bFGF to protect neurons against ischemia/reperfusion injury.  相似文献   

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AIM: To investigate cardiomyocyte apoptosis and the expression of caspase-3, Bcl-2 and Bax after acute myocardial infarction (AMI) in rats.METHODS: AMI model was established with the ligation of left coronary artery in 78 randomly selected female SD rats.Twenty-four hours after operation, 43 survivors were randomly divided into 48-hour and 4-week two groups according to the time points: MI 48 h (n=11) and MI4 weeks (n=13) groups, sham-operated rats (S, n=27) were also randomly selected and reassigned to S48 h (n=10) and S4 weeks (n=10) groups.Cardiomyocyte apoptosis was detected with in situ terminal deoxynucleotidyl transferase (TdT)-dUTP nick-end labeling (TUNEL staining) and DNA gel electrophoresis.Caspase-3, Bcl-2 expression and Bax expression were detected with immunohistochemistry and Western blotting analysis.RESULTS: Compared with sham-operated group, after AMI, systolic, diastolic, and mean arterial blood pressures (SBP, DBP, MAP), left ventricular systolic pressure (LVSP) and the maximum change rate of left ventricular pressure rise and fall (±dp/dt) were significantly decreased (P<0.05, P<0.01), while left ventricular end diastolic pressure (LVEDP) was significantly increased (P<0.05) in MI 48 h group.All the above indices in MI 4 weeks group had the same change as that in MI48h group, with the LVEDP significantly higher (P<0.01), except for a non-significantly change in SBP, DBP and MAP (all P>0.05).In both MI 48 h and MI 4 weeks groups, myocyte apoptotic index was significantly increased in the infracted/scar, border and non-infarcted areas (P<0.05,P<0.01) with caspase-3 and Bax expressions increased significantly (P<0.05, P<0.01) in myocytes of the above three areas and Bcl-2 expression increased only in myocytes of the infracted area in MI 48 h group.Western blotting indicated that Bcl-2/Bax ratio was also decreased in MI 48 h subgroup.CONCLUSIONS: After AMI in rats, cardiomyocyte apoptosis happened in the infarction/scar, border and non-infarcted areas, with caspase-3 and Bax expression in myocytes increased, and with Bcl-2 expression increased in myocytes of infracted area and Bcl-2/Bax ratio decreased only early after AMI.  相似文献   

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AIM: To establish and evaluate a rat model of heart ischemia-reperfusion injury in vivo. METHODS: Seventy-two male Sprague-Dawley rats weighing(250±50)g were randomly divided into sham operation group(sham), ischemia-reperfusion group(I/R) and normal group. The animals were anesthetized and heparinized. Myocardial ischemia-reperfusion was induced by ligating the left anterior descending coronary artery with "U-shape tube" for 35 min followed by 120 min or 240 min reperfusion in vivo. The heart infarct size was measured by triphenyltetrazolium chloride(TTC) staining. The myocardial cell apoptotic index was determined by the method of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling(TUNEL). Immunohistochemical method was used to detect the expression of Bcl-2 and Bax in rat ischemia myocardium. The blood level of MB isoenzyme of creatine kinase(CK-MB),cardiac troponin I(cTnI),nitric oxide(NO),malondialdehyde(MDA), total superoxide dismutase(T-SOD)and glutathione peroxidase(GSH-Px) were detected after reperfusion for 2 h and 4 h. RESULTS: Compared with normal group and sham group, there were obvious changes of ST-T segment and Q wave in the electrocardiogram of I/R group. The blood level of CK-MB, cTnI, NO, MDA and GSH-Px in I/R group increased(P<0.05,P<0.01) after reperfusion for 2 h and 4 h, and the blood level of T-SOD in I/R group after reperfusion for 2 h and 4 h also increased(P<0.05). The heart infarct size in I/R group was the largest as compared to other groups. Among these groups, the apoptotic index of I/R group was the highest and the Bcl-2/Bax ratio in I/R group decreased(P<0.01).CONCLUSION: The rat model of heart ischemia-reperfusion injury in vivo can be successfully established with the "U-shape tube". There are obviously changes of heart infarct size, blood level of CK-MB, cTnI, NO, MDA, T-SOD and GSH-Px, myocardial apoptotic index and Bcl-2/Bax ratio between I/R rats and control animals.  相似文献   

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AIM: To investigate the effect of ligustrazine (Lig) on cerebral injury in LPS-induced septic shock rats and to explore the underlying mechanism.METHODS: Wistar rats (n=48) were randomly divided into control group, LPS group and LPS+Lig treatment group. The rats in LPS group were randomly divided into 2 subgroups at time points of 6 h and 12 h. After ligustrazine treatment, the venous blood was collected by removal of eyeballs to detect the concentration of neuron-specific enolase (NSE) using ELISA. The nitric oxide (NO) concentration in the homogenate of brain tissues was examined. The apoptosis in the hippocampus was analyzed by TUNEL staining. The protein expression of Bax and Bcl-2 was determined by Western blot.RESULTS: Ligustrazine inhibited the elevation of NSE and NO concentrations in LPS-induced septic shock rats. Furthermore, ligustrazine administration also attenuated LPS-induced increase in Bax expression and decrease in Bcl-2 expression. CONCLUSION: Ligustrazine decreases the concentration of NSE and NO, and attenuates cerebral injury in LPS-induced septic shock rats. These effects may be related to the regulation of Bax and Bcl-2 expression.  相似文献   

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AIM: To observe the effects of mesenteric lymph duct ligation on apoptosis of lung tissue,correlated gene expression with apoptosis and TNF-α,IL-6 contents in rats by two-hit.METHODS: 45 Wistar rats were divided into three groups: the ligation group,the non-ligation group and sham group,and the two-hit model was established by means of hemorrhage and LPS treatments.Ligating mesenteric lymph duct was conducted in ligation group.After 24 hours,the pathological sections of lung tissue were prepared for determining the apoptosis rate by TUNEL method and expressions of Bcl-2 and Bax were observed by immunohistochemical test.The lung homogenate was also prepared for determining the contents of TNF-α and IL-6 by ELISA.RESULTS: After two-hit,the apoptosis rate,Bax expression in lung tissue and contents of TNF-α and IL-6 in serum and lung homogenate in non-ligation group were increased and Bcl-2 expression was lower than that in sham group and ligation group significantly (P<0.01,P<0.05).Apoptosis rate in ligation group was no statistics difference with sham group (P>0.05),and the expression of Bcl-2 protein was increased and Bax was lower than that of sham group (P<0.01,P<0.05).CONCLUSION: Blockage of intestinal lymphatic pathway reduces the apoptosis of lung in two-hit rats,and its mechanism might relate to reduced the levels of TNF-α and IL-6 and improved the expression of Bcl-2 protein in lung by the ligation of mesenteric lymph duct.The mesenteric lymph of two-hit might play an important role in the pathogenesis of acute lung injury (ALI).  相似文献   

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AIM: To study age-related changes of expression of Bcl-2, Bax and caspase-3 activity after focal cerebral ischemia/reperfusion (I/R) in aged rats. METHODS: The aged SD rats (20-21 months) and the young animals (4-5 months ) were subjected to 3 h of middle cerebral artery occulsion with the intraluminal filament technique, followed by 3 h, 6 h, 12 h, 24 h and 72 h of referfusion. Expression of Bcl-2, Bax and caspase-3 activity of the young and the aged rats were examined. RESULTS: Cerebral infarct zone increased in the aged at ischemia 3 h and I/R 12 h than that in the young. With I/R time longer, increase in neuron apoptosis showed early and lasted longer in the aged. The Bcl-2 expression increased in the young with I/R time longer, but was not obvious in the aged. Bax expressd obviously and early, and kept on longer in the aged during I/R than that in the young. The enhanced activity of caspase-3 showed early in the aged than that in the young during I/R. CONCLUSION: The mechanisms of serious cerebral injury and neuron apoptosis might be related to the increase in Bax expression and caspase-3 activity.  相似文献   

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AIM: To investigate the protective mechanisms of ginkgolide B (GB) on rat retinal degeneration induced by N-methyl-N-nitrosourea (MNU). METHODS: The rat retinal degeneration model was made. Photoreceptor cell apoptosis was measured by TUNEL assay. The expression of Bcl-2 and Bax in the different time points in the rat retina after treated with MNU was measured by RT-PCR and immunohistochemical methods. RESULTS: The outer nuclear layer cell apoptotic index in GB treatment group was significantly lower than that in model group (P<0.01). The bcl-2/bax mRNA ratios at scheduled time points of 12 h, 1 d, 2 d, 3 d and 5 d after MNU injection in model control were 0.36, 0.15, 0.29, 0.42 and 0.64, respectively, while the ratios in GB group were 0.98, 0.92, 0.53, 0.45 and 0.68, respectively, larger than those in model control group (P<0.01). No Bcl-2 positive expression was detected at any scheduled time points after MNU injection in model control group. Strong positive Bcl-2 expression was detected in GB group 1 d after MNU injection, decreased at the 2nd day and disappeared at the 3rd day. Compared with model control group, the Bax expression in GB group was significantly decreased (P<0.01).CONCLUSION: Ginkgolide B effectively inhibits the apoptosis of photoreceptor cells. The mechanism of GB action may be related to the increase in the expression of Bcl-2 and the increase in the ratio of Bcl-2/Bax.  相似文献   

18.
LI Shu-qing  LI Fan  HE Liang  HE Bo 《园艺学报》2016,32(3):477-484
AIM: To assess whether the expression of tight junction(TJ) proteins, occludin/zonula occludins(ZO)-1, and regional cerebral blood flow(rCBF) link to brain edema in tree shrews during thrombotic cerebral ischemia and ischemic postconditioning(PC), and to explore how TJ affects brain edema and cerebral infarction. METHODS: Tree shrews were randomly grouped into control, ischemia and cerebral ischemia+PC(n=23), and the remaining 3 animals were used for magnetic resonance imaging(MRI). The local cerebral thrombosis were induced by photochemical reaction in the tree shrews, and ischemic PC was established at 4 h after induction of cerebral ischemia followed by clipped ipsilateral common carotid artery(5 min×3). The changes of the neural ultrastructure were observed under electron microscope. The neuronal apoptosis was analyzed by the method of TUNEL. Laser Doppler brain flowmetry was used to monitor the rCBF. The protein levels of occludin/ZO-1 were determined by immunochemistry and Western blot. The cerebral infarction volume was detected by MRI. The brain water content was measured by dry-wet weight method. RESULTS: Induction of cerebral ischemia led to a significant reduction of the normal neuron numbers in the hippocampal CA1 area, and conversely, the number of neurons with abnormal ultrastructure was increased. The TUNEL positive cells were increased significantly(P<0.01) in ischemia group. Moreover, the rCBF decreased significantly(P<0.01), and occludin/ZO-1 protein expression decreased(P<0.01). The brain water content and cerebral infarction volume were significantly increased(P<0.01). Ischemic PC increased the rCBF and the occludin/ZO-1 expression, but reduced the brain water content, the TUNEL positive cells, and the infarction volume(P<0.01). CONCLUSION: Ischemic PC increases the rCBF but not the local water content, suggesting that reduced cerebral infarction volume after ischemia PC is associated with the attenuation of cerebral edema by the enhancement of occludin/ZO-1 protein expression.  相似文献   

19.
AIM: To study the effects of norepinephrine preconditioning(NE-P) and ischemic preconditioning (IP)on apoptosis and Bcl-2, Bax expression in rat myocardial cells in myocardial ischemic reperfusion (I/R). METHODS: The model of rat ischemic-reperfusion was used to conduct NE-preconditioning. Apoptotic myocytes were detected with TUNEL. Bcl-2, Bax expression were detected with immunohistochemistry. RESULTS: The rate of apoptosis cells in I/R group was higher, the rate of apoptosis cells in NE-P group and IP was lower significantly than that in I/R group(P<0.01). The expression of Bcl-2 in I/R group was lower, but the expression of Bax was higher, the expression of Bcl-2 in NE-P group was higher significantly than that in I/R group(P<0.01), the expression of Bax in NE-P group was lower than that in I/R group(P<0.01). There was no significantly difference between NE-P and IP group in the above parameters (P>0.05). CONCLUSION: NE-P reduced myocyte apoptosis by I/R in rats; The expression of Bcl-2 ,Bax genes played an important role in myocardial apoptosis.  相似文献   

20.
AIM: To evaluate the effect of aminoguanidine (AG) on inflammatory factors and neuronal apoptosis after focal cerebral ischemic injury in rats and the possible mechanism of protective effect of AG against cerebral ischemic injury.METHODS: Thirty male SD rats (weighing 250 g-280 g) were randomly divided into three groups: (1) sham operated group (SH group,n=10),(2) ischemic groups (IS group,n=10),(3) AG group (n=10).In AG group,AG at dose of 100 mg·kg-1 was given intraperitoneally twice a day for 3 consecutive days.In IS group,normal saline was given instead of AG.Focal cerebral ischemia was produced by middle cerebral artery occlusion (MCAO) for 12 h.A nylon thread with rounded tip was inserted into left internal carotid artery cranially until resistance was felt.The distance from bifurcation of common carotid artery to the tip of the thread was about 18-19 mm.Focal cerebral ischemia was confirmed by left Horners syndrome and right side hemiplegia.In SH group,the carotid artery was exposed but no thread was inserted.The expression of tumor necrosis factor-α(TNF-α) was determined by immunochemistry and the content of interleulin-1β(IL-1β) was measured by radioimmunoassay.The expressions of Bcl-2 and Bax protein were detected by flow cytometry.RESULTS: The expression of TNF-α and the content of IL-1β were markedly increased after MCAO.Significantly increased DNA fragmentation,the indication of apoptosis,was detected after MCAO.The expression of TNF-α and the content of IL-1β were significantly lower in AG group than those in IS group.The percentage of apoptosis cells and expression of Bax protein were markedly lower in AG group than those in IS group but still significantly higher than those in SH group.The expression of Bcl-2 protein was markedly higher in AG group than that in IS group.No significant difference in the expression of Bcl-2 protein between IS and SH group was observed.CONCLUSION: AG inhibits the increase in the expression of TNF-α and the content of IL-1β,and protects neurons from apoptosis induced by focal cerebral ischemia through increasing the Bcl-2 protein expression and inhibiting the Bax protein expression.  相似文献   

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