首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 93 毫秒
1.
褐黑素对大鼠海马神经元谷氨酸所致毒性的拮抗作用   总被引:2,自引:0,他引:2  
Gao HX  Zhang LX 《生理学报》1999,51(4):430-434
在大鼠海马脑片上电刺激Schaffer侧支纤维,胞外记录CA1区锥体细胞层诱发群体锋电位,观察灌流谷氨酸和褪黑素对PS的影响。结果显示:5.0mmol/L浓度的Glu可使PS值下降至对照值的4.1%;ME(0.4、0.5和0.6μmol/L)一5.0mmol/L浓度的Glu可使PS值下降至对照值的14.7%、105.2%、24.3%;MEL、Glu,与赛庚啶混合给药,PS值下降至0。上述结果提示。  相似文献   

2.
含CD自杀基因腺病毒载体的构建及其应用   总被引:6,自引:0,他引:6  
构建了含CMV启动子、大肠杆菌胞嘧啶脱氨酶(cd)基因的复制缺陷型重组腺病毒载体(AdCMVCD)。经Southern杂交和RT-PCR鉴定证实,cd基因已克隆进入AdCMVCD,并在受染细胞中表达。经氯化铯密度梯度离心法纯化的病毒滴度达1×1015pfu/L。经100m.o.i.的AdCMVCD感染的HeLa和C6细胞株在100μmol/L5FC处理后,细胞存活率<20%。同时也观察到AdCMVCD/5FC系统有很强的旁杀伤效应,将3.3%的AdCMVCD受染细胞与96.7%的野生型细胞混合,经50μmol/L5FC处理后,>60%的细胞被杀死。AdCMVCD/5FC系统的建立为肿瘤基因治疗的研究提供了新的手段。  相似文献   

3.
Qin XM  He RR 《生理学报》2000,52(6):463-467
在23只隔离灌流颈动脉窦区的麻醉大鼠上,观察了链霉素(streptomycin,SM)对动脉压力感受器反射影响的离子机制。结果:(1)用SM(200μmol/L)隔离灌流大鼠颈动脉窦区时,压力感受器机能曲线向右上方移位,曲线最大斜率及反射性血压下降幅度均减小(P〈0.01),提示SM对压力感受器反射的抑制作用;(2)预先灌流高Ca^2+溶液(4mmol/L)后,可部分消除SM(200μmol/L)  相似文献   

4.
褪黑素对大鼠海马神经元谷氨酸所致毒性的拮抗作用   总被引:3,自引:0,他引:3  
在大鼠海马脑片上电刺激Schaffer 侧支纤维, 胞外记录CA1 区锥体细胞层诱发群体锋电位(population spike,PS) , 观察灌流谷氨酸(Glu) 和褪黑素(MEL) 对PS的影响。结果显示:5-0 mmol/L浓度的Glu 可使PS值下降至对照值的4-1 % ; MEL(0-4 、0-5 和0-6 μmol/L) 与5-0 mmol/LGlu 混合给药,PS值分别变化为对照值的14-7 % 、105-2% 、24-3 % ; MEL(0-5 μmol/L) 、Glu (5-0 mmol/L) , 与赛庚啶(CDP,0-5 μmol/L) 混合给药,PS值下降至0 。上述结果提示,5-0 mmol/L浓度的Glu 有神经毒性作用, 但可为MEL拮抗, 这可能由5HT受体所介导。  相似文献   

5.
利用流式细胞术检测线粒体PTP开放   总被引:4,自引:0,他引:4  
用线粒体电位特异必 光探针Rhodamine123标记线粒休后,在改装FACS420流式细胞仪上用C-30数据集集和储存程序采集并存储数据,用C-30分析程序分析得取反映线料体前散射(FSC)、Rhodamine123荧光强度和侧散射(SSC) FSC,FL1和FL2合并图。结果显示,200μmol/LCa^2+处理20分钟使线粒体同时发生FSC增大、Rhodamine123荧光强度降低和SSC增  相似文献   

6.
本工作目的是在离体大鼠肠系膜动脉床灌流模型上,观察几种常见炎症介质:前列腺素E2(PGE2)、缓激肽(BK)、组胺(HIS)、血小板活化因子(PAF)及5-羟色胺(5-HT)对血管周围感觉神经介质CGRP释放的直接影响。结果显示:PGE2(1-100μmol/L)和BK(5-10μmol/L)能引起大鼠肠系膜动脉床时间和浓度依赖性地释放CGRP。HIS,PAF和5-HT则未见明显作用。结果提示,PGE2与BK可能是引起血管周围感觉神经兴奋和CGRP释放的主要炎症介质。  相似文献   

7.
研究了铝胁迫下耐铝性不同的两个小麦品种根细胞液泡膜ATP酶、焦磷酸酶活性和膜脂的变化。与对照相比,经20和100mol/L的AlCl3处理后,耐铝品种Altas66的液泡膜H^+-ATP和和Ca^2+-ATP酶活性迅速下降;铝敏感品种Scout66液泡膜H^+-ATP酶和Ca^2+-ATP酶活性则在20μmol/L时增加,100μmol/L时下降。焦磷酸酶活性在Al-tas66中下降,在Scout  相似文献   

8.
血管紧张素(ANG)Ⅱ在10-10-10-6mol/L范围内剂量依赖性促进无血清培养新生大鼠心肌细胞蛋白质合成速率。蛋白激酶C(PKC)抑制剂staurosporine(Stau2nmol/L)对心肌细胞基础状态3H-Leucine掺入无明显影响,但Stau预处理30min,则可有效阻断ANGⅡ(1μmol/L)对细胞蛋白质合成的刺激作用;单纯应用PKC激活剂PMA(1μmol/L)可使心肌细胞蛋白质合成速率增加,与对照组相比,PMA组3H-Leucine掺入量增加了41.04%。细胞Na+-H+交换抑制剂Amiloride预处理也能阻断ANGⅡ刺激3H-Leucine掺入细胞蛋白质的作用。以上结果提示PKC和Na+-H+交换的激活,可能是ANGⅡ诱发的心肌细胞肥大反应的重要胞内信息转导机制。本工作还观察到,阻断细胞Na+-H+交换后并不影响由PKC激活导致的蛋白质合成增加,提示可能存在着PKC和Na+-H+交换彼此相对独立地调节心肌细胞生长的途径。  相似文献   

9.
采用大鼠海马脑片体外缺血模型,观察海马突触体内蛋白激酶C(PKC)活性的变化,以及这种变化对突触体谷氨酸(GLU)摄取的影响。结果显示:海马脑片体外“缺血”10min,其突触体内PKC活性基本不变,而缺血30min,突触体内PKC活性显著上升(P<0.01,n=6);非N-甲基-D-天门冬氨酸(NMDA)受体拮抗剂DNQX有效地抑制PKC活性的同时,可降低胞外GLU的堆积,而NMDA受体阻断剂AP_5无作用。进一步实验证明,PKC激动剂PDB浓度依赖性地抑制突触体对3H-GLU的摄取(IC50=131±10μmol/L),此抑制作用可由PKC抑制剂H-7(100μmol/L)抵消。提示脑缺血诱发GLU堆积的作用机理可能是:脑缺血引发钙内流导致GLU过量释放,GLU又通过突触前非NMDA受体激活PKC,抑制其自身摄取,正反馈性加重胞外GLU的堆积。  相似文献   

10.
陆玲  黄为一 《菌物系统》2000,19(1):97-101
TFP(10-100μmol/L)可引起裂殖酵母(Schizosaccharomyces pombe)细胞Ca^2+内流,TFP浓度不同,促进Ca^2+内流程度也不一样,50μmol/L TFP的促进作用最大。并且TFP浓度越大,Ca^2+内流出现峰值也越早,10、20、50、100μmol/L TFP处理后,胞内总钙出现峰值时间分别为45、45、30、15分钟。胞外H^+浓度也会对TFP引起的  相似文献   

11.
In each optic lobe and optic peduncle of two aquatic beetles viz. Dineutes indicus and Cybister rugulosus the neurosecretory cells are observed with the help of various histochemical techniques. These cells are arranged to form a discrete group. A group in the optic lobe of both species contains about 25 to 30 neurosecretory cells. On the basis of staining properties the neurosecretory cells are classified into A and B types. These cells stain with chrome haematoxylin-phloxine and paraldehyde fuchsin, but do not stain with azan. Histochemically, the neurosecretory material is positive for proteins and shows a negative reaction for 1,2-glycols. The cells show variations in RNA contents in correlation with the state of secretory activity. Axons of the neurosecretory cell group of the optic lobe are observed directed to the optic peduncle. The axonal tract from neurosecretory cells in the optic peduncle runs towards the lateral margin of the brain.  相似文献   

12.
The rat optic nerve is a useful model for stem cell regeneration research. Direct injection into the rat optic nerve allows delivery into the central nervous system in a minimally-invasive surgery without bone removal. This technique describes an approach to visualization and direct injection of the optic nerve following minor fascial dissection from the orbital ridge, using a conjunctival traction suture to gently pull the eye down and out. Representative examples of an injected optic nerve show successful injection of dyed beads.  相似文献   

13.
神经细胞的特化之一是其轴突,长度可达胞体直径的几百甚至几千倍.轴浆转运维系着胞体和轴突终末之间大量的物质交流,保证神经细胞发挥正常功能.轴浆转运障碍可以导致神经细胞功能受损直至凋亡.在一些视神经疾病中,轴浆转运功能的改变是最早出现的症状,因此也可能成为治疗的潜在靶点.在青光眼和视神经缺血的动物模型中,轴浆转运功能的下降是最早出现的变化之一.而Leber's遗传性视神经病变(LHON)和常染色体显性视神经萎缩(ADOA)是已知线粒体功能障碍引起的视神经疾病.不难想象,长距离轴浆转运功能对能量代谢尤其敏感,因此在LHON和ADOA中可能也有不同程度的下降,但似乎并没有受到足够关注.本文首先回顾了微管和马达蛋白在轴浆转运中的作用,比较分析以上所述几种疾病的发病机制、临床表现及治疗手段,试图发现它们之间的共同特点以及这些特点与能量代谢、轴浆转运之间的潜在关系,为其治疗提供新的思路.  相似文献   

14.
倏逝波光纤免疫传感器作为一种新兴的检测技术,在环境检测、食品卫生检测及生物医学检测等领域具有广泛的应用前景。为了降低检测成本并达到快速检测,光纤再生问题就显得尤为重要。我们在对倏逝波光纤免疫传感器原理和光纤再生原理介绍的基础上,对光纤再生的酸性碱性溶液、高浓度盐溶液、去污剂等方法进行简要综述,探讨了光纤再生存在的问题,并展望了解决光纤重生后倏逝波光纤免疫传感器的应用前景。  相似文献   

15.
16.
《Developmental neurobiology》2017,77(10):1206-1220
Adult neurogenesis occurs more commonly in teleosts, represented by zebrafish, than in mammals. Zebrafish is therefore considered a suitable model to study adult neurogenesis, for which the regulatory molecular mechanisms remain little known. Our previous study revealed that neuroepithelial‐like neural stem cells (NSCs) are located at the edge of the dorsomedial region. We also showed that Notch signaling inhibits NSC proliferation in this region. In the present study, we reported the expression of Wnt and Shh signaling components in this region of the optic tectum. Moreover, inhibitors of Wnt and Shh signaling suppressed NSC proliferation, suggesting that these pathways promote NSC proliferation. Shh is particularly required for maintaining Sox2‐positive NSCs. Our experimental data also indicate the involvement of these signaling pathways in neural differentiation from NSCs. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 77: 1206–1220, 2017  相似文献   

17.
Summary The gross morphology and the fine-structural characteristics of neurones of the second and third optic ganglia of the honeybee Apis mellifera were investigated light microscopically on the basis of Golgi (selective silver)- and reduced silver preparations.The second optic ganglion, the medulla, is ovoid in shape and has a slightly convex distal surface and a slightly concave proximal surface. The medullar outer levels are characteristically composed of neuronal arrangements showing strict precision of their geometrical spacing proximally as far as a pronounced layer of tangential fibre elements comprising the serpentine layer of the medulla. At the inner medullary levels retinotopic channels are again multiplied, and the arrangement of axons and dendrites contribute to a complex lattice.The third optic ganglion, the lobula, is interposed between the medulla and the protocerebrum. It is the site of termination of the third-order neurones. The lobula in hymenopterans appears, in contrast to dipterans, odonates and lepidopterans, as a single neuropilic mass.A short review of the electrophysiological data concerning these two ganglia has been tentatively correlated with some of the anatomical data.  相似文献   

18.
Human telomerase plays an important role in the cancerogenesis as it is up-regulated in 80-90% of malignant tumors. Thus, it is considered as a potential cancer marker and relevant target in oncology. Its task is the extension of guanine-rich strands of the telomere using an intrinsic RNA as the template. In this paper we developed a new biosensoric assay based on total internal reflection fluorescence measuring the activity of the telomerase on sensor surface. Two alternatives to determine the telomeric activity are demonstrated without the use of amplifying steps as e.g. PCR. The enzymatic inclusion of FITC-labeled dUTPs should reveal the synthesis process in real-time indicating the elongation of a phosphothioate telomeric substrate (PS/TS)-modified primer. Additionally the elongated strand was detected by hybridization with a FITC-labeled complementary linear DNA probe. As the telomeric guanine-rich single-stranded DNA adopts intramolecular quadruplex structures, it was necessary for the hybridization to linearize the telomeric DNA by increasing the reaction temperature to 48 degrees C. The comparison of the telomerase activity using labeled and unlabeled nucleotides indicated the inhibition effect of the FITC-labeled nucleotides slowing down the synthesis rate of the enzyme. It is shown with the modified biosensor that the PS/TS primer binds the telomerase from the HL-60 cell lysates, effectively elongating the immobilized primer. Furthermore no more purification steps were required as all measurements were performed with crude cell extract.  相似文献   

19.
A floating fraction that layers on top of 0.25 sucrose has been obtained during the preparation of myelin from intact and 9 day degenerating goldfish optic tracts. The proportion of total tract protein isolated in floating fraction rises from 6.6% to 11.0% during degeneration. This increase is paralleled by a morphologically observed splitting of myelin lamellae. Floating fraction contains all of the major myelin proteins but shows a 40% increase in the proportion of basic protein and a 2–3 fold decrease in the proportion of IP proteins (intermediate molecular weight glycoproteins) and a 36 Kd (X) protein. The lipid to protein ratio is slightly higher in floating fraction than myelin. Lipid composition is characterized by 1/2–1/3 the myelin levels of galactolipids and twofold increased levels of triglycerides and cholesterol esters. Electron microscopy of floating fraction shows a mixture of myelin fragments with few lamellae and single membrane fragments. Taken together the results indicate that floating fraction in the degenerating goldfish optic tract is at least partially derived from the breakdown of myelin.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号