ABSTRACT
AIM: To investigate the effects of sodium hydrosulfide ( NaHS ) , a donor of hydrogen sulfide ( H2 S) , on the membrane permeability , intracellular Ca 2+concentration ( [ Ca2+] i ) and the release of IL-1βinduced by a-denosine triphosphate (ATP) in rat microglia, and to explore the effect of H2S on ATP-P2X purinergic signaling pathway and the molecular mechanism of its neuroprotective effect .METHODS: Rat microglia in logarithmic growth phase were used in the study.The [Ca2+]i was detected by Fura-2/AM staining.Fluorescent dye YO-PRO-1 was used to observe the membrane permeability.Interleukin-1β(IL-1β) was measured by rat IL-1βELISA kits.RESULTS:The YO-PRO-1 flu-orescence intensity was obviously elevated by ATP induction in a dose -dependent manner in the rat microglia , but this effect was counteracted by NaHS pretreatment (P<0.05).[Ca2+]i rapidly increased and then decreased slowly , forming a sta-ble platform for a long time when rat microglia were treated with ATP .Ca2+spike activity induced by ATP had no change , but the platform disappeared (P<0.05) after NaHS pretreatment.The ATP and LPS together facilitated the release of IL-1β, but the phenomenon was inhibited by NaHS (P<0.05).CONCLUSION:Hydrogen sulfide may decrease the mem-brane permeability , calcium inflow and IL-1βrelease in rat microglia activated by high dose of ATP .The cytoprotection of hydrogen sulfide may be mediated by purinergic signaling pathway .
ABSTRACT
Aim To investigate the modulation effects of NaHS on arterial vasodilatation functions of renal hy-pertensive rats .Methods Two-kidney , one-c lip ( 2K1C ) renovascular hypertension was induced .Rats were randomly divided into four group:sham group , two-kidney one-clip model ( 2K1C ) group, 2KIC +NaSH( H2 S donor ) group, PPG group.The systolic blood pressure ( SBP ) was measured before the opera-tion and each week after the operation .The carotid ar-tery was collected for morphometric parameters ( outer radius, wall thickness, the radio of wall thickness to outer radius) and the tension of the carotid artery was observed with the isolated artery ring technique .Immu-nohistochemistry was used to determine the protein ex-pression of eNOS , ET-1 protein in carotid artery .Re-sults The blood pressure of 2K1C group and PPG group was higher than that of sham group ( P<0.05) . Compared with 2K1C group,the blood pressure and the rat arteria carotis communis of the radio of wall thick-ness to outer radius of 2K1C+NaHS group decreased significantly , while the relaxation of carotid artery to ACh in NaHS group increased .According to the immu-nohistochemistry results , eNOS expression was upregu-lated while ET-1 was downregulated in 2K1C +NaHS group as compared with 2K1C group.Conclusions Chronical administration of NaHS can decrease blood pressure in renovasocular hypertensive rats .The anti-hypertensive effect of H 2 S maybe associated with im-provement of the arterial functions .
ABSTRACT
AIM:To investigate the formation of membrane pore in PC 12 cells induced by exogenous adenosine triphosphate ( ATP) and to identify the key molecular targets .METHODS:PC12 cells were treated with different concen-trations of ATP to establish the injury model .The morphological change was observed under an inverted phase -contrast mi-croscope.The viability of the PC12 cells was measured by CCK-8 assay.Fluorescent dye YO-PRO-1 was used to detect the membrane permeability.The expression of P2X7 receptor and pannexin 1 (Panx1) at mRNA and protein levels was as-sessed by real-time PCR and Western blotting .RESULTS:After exposed to ATP (1 mmol/L, 3 mmol/L and 5 mmol/L) for 3 h, the PC12 cells became edematous , and the number of adherent cells decreased gradually in a dose-dependent man-ner .The cell viabilities in 3 mmol/L ATP group and 5 mmol/L ATP group were significantly decreased compared with con-trol group (P0. 05).The expression of P2X7 receptor at mRNA and protein levels was significantly increased (P0.05) when PC12 cells were exposed to ATP for 3 h.CONCLUSION:Extracellular ATP at high concentration may induce membrane pore formation with the expression and activation of P 2X7 receptor in PC12 cells.
ABSTRACT
[ABSTRACT]AIM:ToexaminetheeffectsofhighconcentrationofextracellularATPonhumanneuroblastoma SH-SY5Y cell injury.METHODS: Cultured SH-SY5Y cells were grouped according to the concentrations of ATP and treatment time.The cell viability was detected by CCK-8 assay.The variation of autophagic vacuoles was observed with monodansylcadaverine staining .The cell apoptosis was analyzed by Hoechst 33258 staining.Meanwhile, apoptotic rate was detected by flow cytometry .The levels of caspase-3 and microtubule-associated protein 1 light chain 3-Ⅱ ( LC3-Ⅱ) were determined by Western blotting .RESULTS:Compared with control group , the survival rate of SH-SY5Y cells was signifi-cantly reduced by ATP at different concentrations (3, 6, 9, 12 and 15 mmol/L for 3 h) and different treatment time (1, 2, 3 and 6 h with 6 mmol/L ATP, peaking at 3 h).The autophagic vacuoles of SH-SY5Y cells were significantly increased at 1 h with ATP treatment , trended to decrease over time and returned to control level at 6 h.The protein expression of LC3-Ⅱwas significantly increased at 1 h with ATP treatment , which was consistent with the time points of increasing auto-phagic vacuoles .LC3-Ⅱexpression level gradually decreased at 2~3 h with ATP treatment , and returned to control level at 6 h.Compared with control group , the apoptotic rate and the expression level of caspase-3 were enhanced synchronously . The peak of apoptotic rate occurred at 3 h, and kept until 6 h.The level of cleaved caspase-3 expression peaked at 6 h. CONCLUSION:High concentration of extracellular ATP induces the autophagy and apoptosis of SH -SY5Y cells.The in-creased autophagy shows up , followed by the climax of apoptosis until 6 h.With the prolonged duration of ATP , apoptosis is the main process in the cells .
ABSTRACT
Aim To investigate the protective effects of hydrogen sulfide ( H2 S) on focal cerebral ischemia/reperfusion injury in rats and the possible mechanisms. Methods Male Sprague Dawley rats were divided into three groups randomly: sham-operated group, cerebral ischemia/ reperfusion ( I/R) group and sodium hydro-sulfide ( NaHS ) + I/R group. The left temporary middle cerebral artery occlusion ( MCAO ) model was established by the line-embolism method. After rats were suffered 2h/24h ischemia/reperfusion stress, the mortality rate was evaluated, and the nervous function-al defect degree was evaluated by Longe scoring, the volumes of cerebral infarction was evaluated by 2 ,3 ,5-triphenyltetrazolium chloride ( TTC) staining, and the expression of P2X7 receptor protein in brain tissue was detected by the immunofluorescence method. Results The mortality rate in NaHS + I/R rats ( 29.41%) was obviously lower than those of I/R group ( 42 . 86%) . The nervous defect scores in NaHS + I/R rats were significant lower than those of I/R group ( P <0.05 ) . The volumes of cerebral infarction in NaHS +I/R group (21.88% ±3.53%) were significant lower than those of I/R group ( 36.71% ±3.73%) ( P <0.01 ) . The results of immunofluorescence showed that the positive expression cells of P2X7 receptor protein in cerebral cortex and hippocampal CA1 area of I/R group were significantly higher than those of sham-op-erated group(P<0. 01). However, compared with I/R group, the positive expression cells of P2X7 receptor protein in cerebral cortex and hippocampal CA1 area of NaHS + I/R group were significantly decreased ( P<0. 01). Conclusions H2S exerts the neuroprotective effect on focal cerebral ischemia/reperfusion injury in rats, and the protective mechanism might be associated with down-regulating the expression of P2X7 receptor protein in brain tissue.
ABSTRACT
AIM: To explore the role of NO/ inducible nitric oxide synthase (iNOS) in the metabotromi glutamate receptor 2/3C (mGluR2/3) mediated-brain ischemic tolerance induced by cerebral ischemic preconditioning (CIP), and to observe the influences of α-methyl- (4-tetrazolyl- phenyl) glycine (MTPG), an antagonist of mGluR2/3, on the expression of iNOS during the induction of brain ischemic tolerance. METHODS: Thirty-six Sprague-Dawley rats were subjected to four vessel occluding global brain ischemic model. Thionin staining and immunohistochemistry were used for neuropathological evaluation and assay of iNOS expression in the hippocampal CA1 subregion of the rats. RESULTS: In the sham group, weak expression of iNOS was detected. The expression of iNOS in the CIP and CIP+ischemic insult groups were increased significantly compared with that in the sham group. Administration of MTPG via lateral cerebral ventricle 20 min before CIP blocked the up-regulation of iNOS induced by CIP, but had no influence on the pyramidal neuron survival. However, in the MTPG+CIP+ischemic insult group, the expression of iNOS was extremely intensive compared to that in CIP and MTPG+CIP groups. Importantly, this up-regulation was accompanied with obvious delayed neuronal death. CONCLUSION: NO/iNOS pathway plays an important role in the process of mGluR2/3 mediated-brain ischemic tolerance induced by CIP.
ABSTRACT
Objective To observe the characteristic changes in cardiac function and to raise diagnostic accuracy and sensibility.Methods 39 silent myocardial ischemia and 58 angina and 46 age-matched healthy subjects and 62 obsolete myocardial infarction underwent myocardial tomography imaging and gated ventricular imaging.Covariance analysis was used to compare difference between SPECT imaging and parameters of function.The age was tested as covariate factor,then SNK-Q test and multiple comparison were carried on.Results The silent myocardial ischemia and angina showed reversible radioactive defect or fixed defect.Most of myocardial SMI showed single peak exempt TPFR.EF,PFR and PER showed remarkably statistical difference (P<0.01).The multiple comparison of PFR and PER was increased according by OMI,AN,SMI and negative control group (P<0.05).Conclusions The myocardial damage and PFR,PER in SMI is lower than that in AN group,which have no remarkably influence on the parameters of diastolic and retractile function in left ventricular.
ABSTRACT
After treatment for 3 months in the patients with impaired glucose tolerance (IGT), plasma glucose, insulin and homeostasis model assessment for insulin resistance (HOMA-IR) were decreased both in rosiglitazone therapy group and in the group treated with rosiglitazone combined with body weight control.Those parameters in the latter group were decreased more significantly than those in the former.Rosiglitazone ameliorates the insulin resistance in patients with IGT, which is further improved when combined with body weight control.
ABSTRACT
Objective To evaluate the clinical diagnosis value of 99mTc-single photon emission computed tomography(SPECT)brain blood perfusion imaging in intractable paroxysmal epilepsy and analyse the imaging character.Methods Two hundred and thirty-eight intractable paroxysmal epilepsy patients performed99mTc-SPECT,MRI,CT,and electroencephalogram(EEG).The results of examinations were ana lyzed and compared.Results The positive rate of epileptic focus in brain SPECT blood perfusion imaging in the generalized tonic-clonic seizure,absence seizure,partial seizure and complex partial seizure were 85.7%,95.7%,89.8%and 90.9%,the positive rate were much higher than those in other methods(P＜0.01).The 23 patients with SPECT focus were carried on a-γ-knife treatment with follow-up for more than one year,and the efficient rate was 78.26%.Conclusions The detection sentivity of SPECT is distinctively higher than that in others.SPECT has an important clinical value to define target region of the stereotaxic radio surgery.
ABSTRACT
BACKGROUND: Brain trauma can stimulate the proliferation of neural stem cells (NSCs) to some extent, while progesterone can ameliorate the learning and memory function following brain trauma, which can also promote the neurofunctional recovery after brain trauma by stimulating the proliferation of NSCs.OBJECTIVE: To observe the effects of progesterone on the proliferation of NSCs after diffuse brain injury (DBI).DESIGN: Randomized control animal experiment.SETTING: Xinxiang Medical College.MATERIALS: Forty-eight healthy male SD rats at 4-5 months with the body mass of 280-330 g were selected.METHODS: The experiment was conducted in Xinxiang Medical College from September 2004 to January 2005. Forty-eight rat models of Marmarou DBI were selected and randomly divided into 4 groups with 12 rats in each group: ①Sham-operation group: rats were cut open the scalp and then sutured.②Brain trauma group: rats were made into animal models of brain trauma.③Dimethyl sulphoxide (DMSO) group: rats were given intraperitoneal injection of DMSO at the same volume as progesterone group at one hour after brain trauma and then the same administration was performed daily. ④Progesterone group: rats were intraperitoneally injected with 4 mg/kg progesterone at one hour after brain trauma and then the same administration was performed daily. Rats were executed respectively at 3 and 6 days after sham operation or brain trauma operation, and hematoxylin-eosin staining was conducted to observe the morphological changes of cortical neurons in brain. The expressions of nestin in dentate gyrus and hippocampus were detected with immunohistochemical staining.MAIN OUTCOME MEASURES: Observation of histomorphological changes of neurons and detection of the expressions of nestin in hippocampus and dentate gyrus.RESULTS: ①There was no injury in cortical neurons in the sham-operation group, while obvious neuronal injury and loss in cortex of rats were found in the 3-day and 6-day brain trauma groups, and the neuronal injury was significantly severer in brain trauma than in 3-day and 6-day progesterone groups. ②The expressions of nestin in hippocampal CA4 region or dentate gyrus of sham-operation group were in low level or little, and the expression of nestin could be seen occasionally in hippocampal CA4 region. The expressions of nestin in hippocampal CA4 region and dentate gyrus of the brain trauma group significantly increased (P ＜ 0.05), while those in the progesterone group increased more than the brain trauma group remarkably (P ＜ O.05).③There were no differences in neuronal injury and nestin expression between braintrauma group and DMSO group(P ＞ 0.05).CONCLUCION: Progesterone for brain trauma may be related with its promoting effects on the proliferation of NSCs.
ABSTRACT
BACKGROUND: Metabotropic glutamate receptor(mGluR) is G-protein coupled membrane receptors, which participate in various physiology or pathology process in brain, but how it induce brain ischemic tolerance(BIT)is unclear.OBJECTIVE: To study roles of mGluR2/3 and mGluR1/5 in the BIT induction.DESIGN: Randomized controlled study based on experimental animals.SETTING: Neurological department of provincial hospital and pathophysiological department of basic institute in a university.MATERIALS: The study was conducted at the Pathophysiological Department, Institute of Basic Medicine, Hebei Medical University from May 2002 to May 2003. Totally 64 healthy male SD rats were selected from the Experimental Animal Center of Hebei Medical University. Glial fibrillary acidic protein (GFAP) antibody, MTPG and(s)-4C3HPG were got from Sigma Company.INTERVENTIONS: 4 vessel occlusion(4VO) brain ischemic models in rats stained with thionine staining and GFAP immunohistochemistry staining. were used. Sixty-four rats, of which bilateral vertebral arteries were occluded permanently by electrocautery, were divided into the following 8groups: sham operation group, cerebral ischemic preconditioning(CIP)group, ischemic insult group; BIT group; MTPG + sham operation group;MTPG+BIT group; MTPG+ischemia group and(s) -4C3HPG+BIT coup. All the rats were killed 7 days after the operation or the final ischemic treatment. Cerebral sections were selected and stained with thionine staining and GFAP immunohistochemistry staining.MAIN OUTCOME MEASURE: The changes of the morphologic hippocampal pyramidal cell and GFAP expression of astrocyte.RESULTS: ① The 8 minutes ischemic insult increased the histological grade(HG) in CA1 area, decreased the pyramidal neuronal density(ND)and increased the expression of GFAP significantly( P ＜ 0.05) . ② The above changes were not observed in the BIT group, indicating that the CIP could protect pyramidal neurons against the 8-minute ischemic insult. ③The protective effects of the CIP were blocked by MTPG or(s)-4C3HPG, as manifested by significant increases in HG and decreases in ND in the groups of MTPG + BIT, MTPG + ischemia and(s)-4C3HPG + BIT( P ＜ 0.05).CONCLUSION: MTPG or (s) -4C3HPG could block the induction of BIT induced by CIP, but mGluR2/3 or mGluR1/5 could participate in the induction of BIT by which protect effect of mGluR is further induced.
ABSTRACT
AIM: To explore the neuroprotective action of progesterone(PROG), which has been proved to be a "neuroactive steroid". METHODS: The model of focal cerebral ischemia was established in rats by reverserble inserting a nylon thread with a diameter of 0.2 mm into the anterior cerebral artery through the internal carotid artery. The effect of PROG was assessed by determining water,sodium, potassium, and calcium contents in striatum of rats subjected to 2 h ischemia followed by 22 h reperfusion. RESULTS: The water,sodium,and calcium contents of middle cerebral artery occlusion(MCAO) striatum were obviously higher,the potassium content was obviously lower than those of non-MCAO striatum in I/R and DMSO groups,but there was no significant difference between these two groups.Compared with the result in I/R and DMSO groups , water, sodium and calcium contents significantly decreased, but potassium(P0.05). CONCLUSION: Treatment with PROG can significantly reduce the striatal injury of rats with cerebral ischmia-reperfusion.
ABSTRACT
AIM: To explore the effect of allicin on hippocampal neuronal apoptosis induced by global cerebral ischemia - reperfusion and its mechanisms. METHODS: Wistar rats were subjected to 15 min global cerebral ischemia followed by 72 h reperfusion. Flow cytometry (FCM) was used to evaluate the rate of hippocampal neuronal apoptosis and colorimetric method was used for the measurement of nitric oxide (NO) , malondialdehyde (MDA) contents and superoxide dismutase (SOD) activity in hippocampal tissue. RESULTS: Neuronal apoptotic rate, nitric oxide and malondialdehyde contents in hippocampal tissues of rats in I - R group were significantly higher than those in sham group. However, superoxide dismutase activity in hippocampal tissues of rats in I - R group was obviously lower than that in sham group. Allicin pretreatment inhibited the above changes in a dose-dependent manner. CONCLUSION: Allicin hihibits hippocampal neuronal apoptosis induced by global ischemia-reperfusion insult through anti - oxidation. The anti - oxidation action of allicin may be one of the mechanisms of inhibitory effects on hippocampal neuronal apoptosis.
ABSTRACT
AIM: To explore the role of NO in the induction of brain ischemic tolerance (BIT) by observing changes of NOS activity and NO_2-/NO_3- content following a transient cerebral ischemia. METHODS: The rat 4-vessel occluding brain ischemic model was used. 140 male Wistar rats were divided into sham, cerebral ischemic preconditioning (CIP), ischemic insult and CIP+ischemic insult groups. An occlusion of the 4 vessels for 3 min was normally used as CIP, and a relative long one for 10 min was used as ischemic insult. When CIP was followed by ischemic insult, the interval between them was 3 d. The CA1 region of the hippocampus of rats was dissected out at 0 h, 2 h, 16 h, 24 h, 36 h, 72 h and 7 d after the last time of ischemia to assay its NOS activity and NO_2-/NO_3- content. RESULTS: The NOS activity and NO_2-/NO_3- content began to increase at 16 h, peaked at 24 h and decreased to basal level at 36 h of reperfusion after CIP. The duration of the up-regulation of NOS activity and NO_2-/NO_3- content was much shorter than that of BIT, which usually takes place 1-7 d after CIP. The pattern of upregulation of the NOS activity and NO_2-/NO_3- content was similar to the CIP group, but the maximum (24 h) was much more than that in CIP group (P