共查询到19条相似文献,搜索用时 140 毫秒
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川楝素与肉毒毒素在神经肌肉接头相互作用的超微结构观察 总被引:3,自引:0,他引:3
本实验用电子显微镜观察了小鼠在不同时间给以川楝素和肉毒毒素后,膈肌神经肌肉接头超微结构的改变。给川楝素后立即或1小时后给毒素,其改变与单给川楝素小鼠的相似。主要是突触小泡明显减少,长管形泡较多,髓膜样或自噬体样结构经常可见等变化。但是,如果先给毒素,5小时或24小时后再给川楝素,则突触小泡平均密度比单给川楝素小鼠的高约90%。表明预先作用于神经肌肉接头的肉毒毒素对川楝素引起的突触小泡减少有阻碍效应。其他改变与单给川楝素的相似。 相似文献
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川楝素是来源于传统中药,楝属植物川楝韧皮的一种三帖化合物。已有研究证明,它是一个作用于神经递质释放环节的特异性突触前阻断剂;并具有抑制人的多种肿瘤细胞增殖和引发细胞凋亡的效应;虽与同为突触前阻断剂的肉毒神经毒素在许多方面有相似的作用特点,但川楝素却又显示有效的抗肉毒效应。本工作利用免 相似文献
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《中国医药工业杂志》1980,(5)
本品系从眼镜蛇蛇毒中分离提纯的一种低分子量蛋白质(神经毒素)并配以无机盐的制剂。【作用特点】眼镜蛇神经毒素是作用非常专一的碱性毒素。它特异地作用于神经肌肉接头的突触后膜,产生箭毒样神经肌肉阻断作用。本品突出的特点是非麻醉性镇痛药,镇痛效果比吗啡强,具有不成瘾、无耐药性、无明显副作 相似文献
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研究突触可塑性的神经肌肉染色法的改进050021河北省医学科学院病生理研究室杨世方,闵宝珍突触可塑性研究是近年来神经生理学及神经病理学中十分重要的课题,以骨骼肌的神经肌肉接头为标本、测量神经末梢的分支点、终板长度及终板发芽率是研究突触可塑性的主要方法... 相似文献
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任何一种作用于神经肌肉接头,导致横纹肌对来自躯体运动神经的冲动不产生反应的物质,均称为神经肌肉阻滞剂。它们可作用于神经肌肉接头前或接头后。仅作用于接头后的阻滞剂具有临床应用价值,常在手术时用作肌肉松驰剂。作用于接头后的阻滞剂可分两类:一类为去极化型肌松药,其代表药物是十烃季铵 相似文献
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神经肌肉接头前阻断剂川楝素抑制大鼠大脑皮层突触体谷氨酸释放(英文) 总被引:2,自引:0,他引:2
目的 阐释川楝素的作用机制 ,为了解递质解释的基本过程提供线索。方法 以大鼠大脑皮层匀浆经密度梯度离心分离获得的突触体作为研究标本 ,分别施加 5 0mmol·L- 1KCl,1.5 μmol·L- 1卡西霉素或 7.5mmol·L- 14 氨基吡啶触发谷氨酸 (Glu)释放。通过检测由Glu氧化脱氢反应与NAD+ 生成的NADH荧光变化测定Glu释放量。结果 川楝素浓度、时间依赖地显著抑制由KCl诱发的Glu释放 ,并主要抑制钙依赖性释放 ;由卡西霉素直接提升胞内钙离子浓度而诱发的Glu释放也被川楝素明显抑制。结论川楝素抑制中枢突触Glu释放 ,该效应与其导致的递质释放机制中钙离子敏感性降低有关。 相似文献
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本文报道用高速液相色谱测定了川楝素含量的各地楝树样品水提物及几种川楝素产品对菜青虫的生物活性,讨论了川楝素含量与生物活性的关系。叶、果样品中虽不含或仅含少量川楝素,但对试虫仍表现出一定的活性。皮中含有较丰富的川楝素,其含量与拒食活性呈正相关,但与毒效作用不相关。四川样品川楝素含量及生物活性均很高而值得重视。川楝素粗产品相对于纯川楝素而言对试虫具更高的生物活性。这种川楝素含量与活性的非线性关系说明样品中其它成份也具活性或与川楝素有着协同作用。通过测定、分析和讨论,指出用川楝素粗产品防治菜青虫是一经济、有效,可行的措施。文中应用了评判援效型杀虫剂的新方法,供讨论和参考。 相似文献
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本文对川楝素的来源、发现、提制、生产、应用及药理、毒理、毒性等方面的研究历史、现状及展望作了简单叙述。旨在讨论进一步研究这一天然化合物的重要意义。特别是通过对川楝素在医学上的药理、毒性等方面研究成果的回顾、总结,而为深入研究其在害虫防治方面的作用机制及应用措施提供依据、寻找线索、开创思路。 相似文献
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应用高速液相色谱(HPLC)对我国楝属(Melia)植物主要分布区的川楝、苦楝的树皮、果实及叶片中川楝素含量进行了测定。结果表明,采自不同地区川棘、苦楝样本中川楝素的含量差别较大。树皮中的含量以贵州(沿河),陕西(西乡)采的苦楝及河南(扶沟)采的川楝较高,分别为5.160、4.697和4.223mg/g。果实中川楝素的含量都较低,苦楝果中仅含微量或测不出。杭州采的川楝果中川楝素含量却显著高于其它楝果样本,而且比其树皮的含量还高(分别为0.800和0.574mg/g)。所采的楝叶中在该测定条件下测不到川楝素存在。楝科中其它9种非楝属植物树皮中不含有川楝素。从整个测定结果可以看出,川楝素只存在于楝属植物树皮中,果中也有少量分布,川楝中川楝素的含量不一定高于苦楝。各样本中川楝素含量的差异是否与其分布区的地理环境、气候及土壤等因素有关,有必要作进一步研究。 相似文献
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The long-term effect of toosendanin on current through nifedipine-sensitive Ca2+ channels in NG108-15 cells. 总被引:4,自引:0,他引:4
Toosendanin is a triterpenoid derivative extracted from Melia toosendan Sieb et Zucc. Previous studies demonstrated that toosendanin could block neurotransmission and stimulate PC12 cell into differentiation and apoptosis. These actions of toosendanin were suggested to result from a continuous increase in Ca2+ influx, which led to intracellular Ca2+ overload. Here, we observed the long-term effect of toosendanin on Ca2+ channels in NG108-15 cells by whole-cell patch-clamp recording. Obtained data showed that a prolonged exposure to toosendanin induced a continuous increase in the Ca2+ influx in a concentration and time-dependent manner while a brief treatment induced an irreversible increase in Ca2+ influx in differentiated NG108-15 cells. The nifedipine-sensitive L-type currents were significantly increased after exposure to TSN while the nifedipine-resistant or omega-conotoxin MVIIC-sensitive currents were not affected. 相似文献
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Toosendanin (Tsn), a triterpenoid extracted from Melia toosendan Sieb et Zucc, possesses different pharmacological effects in human and important values in agriculture. However, liver injury has been reported when toosendanin or Melia-family plants, which contain toosendanin are applied. The mechanism by which toosendanin induces liver injury remains largely unknown. Here we reported that toosendanin induced primary rat hepatocytes death by mitochondrial dysfunction and caspase activation. Toosendanin led to decrease of mitochondrial membrane potential, fall in intracellular ATP level, release of cytochrome c to cytoplasm, activation of caspase-8, 9, and 3 and ultimately cell death. Level of reactive oxygen species (ROS) was also increased in hepatocytes after incubation with toosendanin. Catalase, the H2O2-decomposing enzyme, can prevent the reduction in ATP level and protect hepatocytes from toosendanin-induced death. The ERK1/2 (p44/42 MAP kinases) and JNK (c-Jun N-terminal kinase) were activated, but p38 MAPK was not activated by toosendanin. Inhibition of ERK1/2 activation sensitized hepatocytes to death and increased activity of caspase-9 and 3 in response to toosendanin. Inhibition of JNK attenuated toosendanin-induced cell death. These results suggested that toosendanin causes death of primary rat hepatocytes by mitochondrial dysfunction and caspase activation. Generation of ROS and MAP kinases activation might be involved in this process. 相似文献
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目的:对采用液相色谱.串联质谱联用法测定川楝子中川楝素含量进行不确定度评估.方法:对川楝子中川楝素含量进行不确定度的分析与评定.结果:川楝素的扩展不确定度为0.003 6%,检测结果可表示为(0.0908±0.003 6)%.结论:建立的不确定度评估方法可用于液相色谱-串联质谱联用法测定川楝子中川楝素含量的不确定度评估,测量不确定度评定方法的确立对于中药质量标准的研究具有重要意义. 相似文献
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Growth Inhibition and Apoptosis-Induced Effect on Human Cancer Cells of Toosendanin,a Triterpenoid Derivative from Chinese Traditional Medicine 总被引:3,自引:0,他引:3
Summary Toosendanin, a triterpenoid derivative isolated from the barks of Melia toosendan Sieb et Zucc, has been used as an anthelmintic vermifuge against ascaris for more than fifty years in China. In the present study, we
investigated the growth inhibition and apoptosis-induced effect of toosendanin on human cancer cells. The result showed that
toosendanin significantly suppressed the proliferation of tested human cancer cell lines. The IC50 values were less than 1.7 × 10−7 M and U937 was the most sensitive cell line with a IC50 of 5.4 × 10−9 M. Flow cytometric analysis revealed that treatment of U937 cells with toosendanin resulted in a dose- and time-dependent
accumulation of cells in the S phase with a concomitant decrease in cells processing to G0/G1 phase. The growth inhibition of U937 cells after exposure to toosendanin was subsequently associated with the induction of
apoptosis, as evidence by the typical condensed and fragmented nuclei, DNA fragmentation, and exposure of phosphatidylserine
on the outer leaflet of plasma membrane. All these results indicated that toosendanin could serve as a potential candidate
for anticancer drug. 相似文献
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目的:采用反相高效液相色谱法建立金铃子汤中原阿片碱、黄连碱、巴马汀、延胡索乙素、川楝素含量同时测定的方法。方法:采用Kromasil C18(250 mm×4.6 mm,5μm)色谱柱,流动相为乙腈-0.05%醋酸水溶液(氨水调pH 6.0),梯度洗脱,流速0.8mL·min-1,检测波长230 nm,柱温30℃。结果:原阿片碱、黄连碱、盐酸巴马汀、延胡索乙素、川楝素质量浓度分别在1.76~35.2,1.84~36.8,2.20~44.0,2.24~44.8,8.48~63.6μg·mL-1范围内线性良好(r=0.9998~0.9999);平均回收率(n=6)分别为103.5%,101.2%,102.7%,100.9%,97.1%。结论:本方法简单快捷,测定结果准确,适用于金铃子汤中原阿片碱、黄连碱、巴马汀、延胡索乙素、川楝素的含量测定,可为金铃子汤的质量控制或中药配伍等方面给与全面、客观的评价。 相似文献