共查询到19条相似文献，搜索用时 501 毫秒
1.
代书新 《淮北职业技术学院学报》2006,5(3):80-80
1、NO的生化生理特性体内多种组织细胞中均存在NO合酶(NO S),包括血管内皮细胞、巨噬细胞、中性粒细胞、血小板、中枢及外周神经系统。NO在体内的生理作用非常广泛,对血液循环系统的正常功能起重要的调节作用,包括:(1)调节血管张力。血管内皮细胞在基础状态下可持续释放NO,以维 相似文献
2.
目的探讨银杏叶黄酮单体成分槲皮素体外对人肝癌细胞HepG2增殖与凋亡的影响。方法将银杏叶黄酮单体成分槲皮素作用于体外培养的人肝癌细胞HepG2,MTT法检测其对HepG2细胞增殖的影响,缺口末端核苷标记（TUNNEL）法检测其对HepG2细胞凋亡的影响。结果银杏叶黄酮单体成分槲皮素使体外培养的人肝癌细胞HepG2的增殖效率下降,使凋亡细胞数增加（P〈0.01）,两者均呈剂量依赖效应。结论银杏叶黄酮单体成分槲皮素具有与银杏叶总黄酮相似的作用,对体外培养的人HepG2细胞增殖有抑制作用,并能诱导细胞凋亡。 相似文献
3.
一氧化氮在神经生物学中的作用 总被引：1，自引：0，他引：1
八十年代末，生命科学领域中一件令人瞩目的事情是发现了一氧化氮（NO）在脊椎动物中的作用，特别是在神经系统中的作用。NO是一种结构简单的气体物质，其特点是易扩散、反应性强、很不稳定，半衰期仅几秒，这使人难以想象它所具有的生物信息作用。何况，NO易转化成硝酸盐和亚硝酸盐，使之成为空气中的有害成份而声名狼籍。然而近几年大量研究表明，哺乳动物中NO可能在许多方面发挥作用。例如，免疫系统通过释放NO消灭病原体；血管内皮细胞通过NO使血管平滑肌松驰，血管扩张；在神经系统中，NO可能起着神经递质的作用。一、NO的生物… 相似文献
4.
血管内皮细胞生长因子（VEGF）又叫血管通透性因子（VPF）,是一种高度特异性地作用于血管内皮细胞的多功能因子。具有使微静脉、小静脉通透性增加,促进血管内皮细胞分裂、增殖、细胞质钙聚集,以及诱导血管生成等作用。VEGF最初从牛垂体滤泡增殖细胞的条件培养液中获得,与先前克隆的血管通透性因子（VPF）的氨基酸序列一致,故两者实为同种。VEGF是血小板源生长四千（PDGF）家族的一个成员。1VEGF的分类及其结构特征人VEGF基因位于染色体6q21.3,全长14kd,由8个外显子、7个内含子组成。编码产物为34～46kd的均质二聚体糖蛋… 相似文献
5.
采用DR法和NBT光照还原法分别测定了槲皮素与Mn（Ⅱ）、Co（Ⅱ）、Ni（Ⅱ）、Cu（Ⅱ）、Zn（Ⅱ）的配合物对·OH和过氧基O2·^-的去除率,并与槲皮素进行了比较。结果表明：对不同体系产生的自由基·OH和O2·^-,合成的六种金属配合物都能在特定的浓度范围起到最佳的去除作用。 相似文献
6.
7.
应用免疫组化方法,比较性地研究了大肠癌组织及其同一患者形态正常大肠粘膜组织中血管内皮细胞生长因子的表达,分析血管内皮细胞生长因子表达与大肠癌发生的年龄、性别、病理分期等因素的关系。结果显示,癌组织与正常大肠粘膜的血管内皮细胞生长因子表达存在明显差异,血管内皮细胞生长因子的表达与大肠癌患者年龄、性别、分化程度等因素不存在相关性,而与Ducks分期存在明显相关性。表明肿瘤血管的生成在大肠癌的生长发展方面起着至关重要的作用,血管内皮细胞生长因子的检测可以作为大肠癌诊断的重要参考指标。 相似文献
8.
川芎嗪（Ligustrazine,LT）是植物川芎根茎中提取的有效成分,近年来,大量的研究证实川芎嗪能够显著减轻脑缺血再灌注损伤后血管内皮细胞与白细胞的黏附作用,对缺氧缺血性脑损伤具有保护作用、能够影响脑缺血再灌注后神经细胞凋亡及脑组织Fos蛋白、c-jun蛋白、Bcl-2蛋白及Fas-L蛋白的表达,影响一氧化氮合酶（... 相似文献
9.
血管内皮细胞生长因子（VEGF）是一种高度特异作用于血管内皮细胞的多功能因子,与内皮细胞的FLT_1和FLK_1受体有高度的亲和力．总结了VEGF的结构特点、分类、体内分布与表达以及生物学功能． 相似文献
10.
谭君 《重庆第二师范学院学报》2006,19(6):11-12,15
槲皮素对金属离子具有强烈的螯合作用。本文研究表明在pH4．6的HAc—NaAc缓冲液中，槲皮素能与Cu（Ⅱ）形成稳定的配合物，在紫外光谱中其吸收带Ⅰ比单独槲皮素红移了59nm。采用等摩尔连续变化法测得槲皮索-Cu（Ⅱ）配合物的配位比为2：1，采用平衡移动法测得配合物的稳定常数为2．0410^8。并初步探讨了槲皮素与Cu（Ⅱ）配位的部位是30H～4C=0。 相似文献
11.
Cytocompatibility of regenerated silk fibroin film: a medical biomaterial applicable to wound healing 总被引：2，自引：0，他引：2
Tie-lian Liu Jing-cheng Miao Wei-hua Sheng Yu-feng Xie Quan Huang Yun-bo Shan Ji-cheng Yang 《Journal of Zhejiang University. Science. B》2010,11(1):10-16
Objective:To explore the feasibility of using regenerated silk fibroin membrane to construct artificial skin substitutes for wound healing, it is necessary to evaluate its cytocompatibility. Methods:The effects of regenerated silk fibroin film on cytotoxicity, adhesion, cell cycle, and apoptosis of L929 cells, growth and vascular endothelial growth factor (VEGF) expression of ECV304 cells, and VEGF, angiopoietin-1 (Ang-1), platelet-derived growth factor (PDGF) and fibroblast growth factor 2 (FGF2) expressio... 相似文献
12.
Homoharringtonine (HHT) has currently been used successfully in the treatment of acute and chronic myeloid leukemias and has been shown to induce apoptosis of different types of leukemic cells in vitro. Emerging evidence suggests that angiogenesis may play an important role in hematological malignancies, such as leukemia. How ever, whether HHT can relieve leukemia by anti-angiogenesis is still unknown. We investigated the anti-angiogenesis potential of HHT with the human umbilical vein endothelial cell line (ECV304) and leukemic cell line (K562) in vitro. Cellular proliferation was determined by MTT assay and apoptosis was analyzed by flow cytometry. The mRNA expression of vascular endothelial growth factor (VEGF) was assessed by RT-PCR and VEGF protein production was detected by Western blot. Inhibition of cell proliferation and induction of apoptosis by HHT were discovered in ECV304 cells, and appeared in a dose- and time-dependent manner. Also, treatment with HHT caused down-regulation of VEGF mRNA expression in K562 cells in similar dose- and time-dependent manner and inhibition of VEGF protein production in K562 cells in response to the enhancing concentration of HHT. The results demonstrated that HHT could also induce apoptosis in endothelium and down-regulate VEGF expression in K562 cells. In conclusion, we believe HHT has anti-angiogenesis potential and speculate that HHT might exert its anti-leukemia effects via reduction of angiogenesis. 相似文献
13.
Homoharringtonine induces apoptosis of endothelium and down-regulates VEGF expression of K562 cells 总被引：1，自引：0，他引：1
INTRODUCTION Homoharringtonine (HHT) is a cephalotoxin alkaloid with anti-leukemic activity and had been used successfully in the treatment of acute and chronic myeloid leukemias (O払rien et al., 1995; 1999; Feldman et al., 1992). The principal mecha-nism of action by HHT is the inhibition of protein synthesis in a dose- and time-dependent manner by binding to ribosome and inhibiting polypeptide chain elongation (Tujebajeva et al., 1989; Zhou et al., 1995). HHT had been shown to indu… 相似文献
14.
15.
以蚕豆叶片下表皮为材料,借助表皮条分析、免疫细胞化学染色、细胞核染色和激光扫描共聚焦显微镜技术,对一氧化氮(nitric oxide,NO)在光暗调控的蚕豆气孔运动中的作用进行探索。实验证明,NO专一性清除剂2,4-羧基苯-4,4,5,5-四甲基咪唑-1-氧-3-氧化物(cPTIO)和一氧化氮合酶(NOS)抑制剂NG-氮-L-精氨酸-甲酯(L-NAME)能够逆转黑暗诱导气孔关闭的效应,并能阻断黑暗诱导的蚕豆保卫细胞NO水平的提高。但二者对光下气孔孔径几乎没有影响。结果表明,光暗调控的蚕豆气孔运动与保卫细胞胞质内的NO水平有关,在保卫细胞细胞核中存在诱导型一氧化氮合酶(inducible-nitric oxide synthase,iNOS),而光暗条件下iNOS活性不同,进而引起NO水平变化并最终影响气孔开关。 相似文献
16.
Shan-zhi Gu Xin-han Zhao Ling-xiao Zhang Li Li Zhi-yu Wang Min Meng Gai-li An 《Journal of Zhejiang University. Science. B》2009,10(3):159-167
Objective: To study the effects of the generation 4 polyamidoamine/vascular endothelial growth factor antisense oligodeoxynucleotide (G4PAMAMNEGFASODN) compound on the expressions of vascular endothelial growth factor (VEGF) and its mRNA of breast cancer cells and on the inhibition of vascular endothelial cells. Methods: We examined the morphology of G4PAMAM/VEGFASODN compound and its pH stability, in vitro transfection efficiency and toxicity, and the expressions of VEGF and its mRNA. Methyl thiazolyl tetrazolium assay was used to detect the inhibitory function of the compound on vascular endothelial cells. Results: The compound was about 10 nm in diameter and was homogeneously netlike. From pH 5 to 10, it showed quite a buffered ability. The 48-h transfection rate in the charge ratio of 1:40 was 98.76%, significantly higher than that of the liposome group (P<0.05). None of the transfection products showed obvious toxicity on the cells. The expressions of both VEGF protein and its mRNA after G4PAMAM/VEGFASODN transfection decreased markedly. Conclusion: With a low toxicity, high safety, and high transfection rate, G4PAMAMNEGFASODN could be a promising gene vector. Specifically, it inhibits VEGF gene expression efficiently, laying a basis for further in vivo animal studies. 相似文献
17.
Tong-liang Bu Yu-dong Jia Jin-xing Lin Yu-ling Mi Cai-qiao Zhang 《Journal of Zhejiang University. Science. B》2012,13(4):318-326
As a component of diesel exhaust particles, 3-methyl-4-nitrophenol (4-nitro-m-cresol, PNMC) is also a metabolite of the insecticide fenitrothion and imposes hazardous effects on human health. In the
present study, the alleviative effect of a common antioxidant flavonoid quercetin on mouse germ cells intoxicated by PNMC
was investigated. Results showed that a single intraperitoneal injection of PNMC at 100 mg/kg induced severe testicular damage
after one week. PNMC-treated mice showed a significant loss of germ cells (approximate 40% loss of round germ cells). PNMC
caused an increase of hydroxyl radical and hydrogen peroxide production and lipid peroxidation, as well as a decrease in glutathione
level, superoxide dismutase and glutathione peroxidase activities. Furthermore, treatment of PNMC increased expression of
the pro-apoptotic protein Bax and decreased expression of the anti-apoptotic protein Bcl-XL in germ cells. In addition, testicular
caspase-3 activity was significantly up-regulated and germ cell apoptosis was significantly increased in the PNMC-treated
mice. In contrast, combined administration of quercetin at 75 mg/kg significantly attenuated PNMC-induced testicular toxicity.
These results indicate that the antioxidant quercetin displays a remarkable protective effect on PNMC-induced oxidative damage
in mouse testes and may represent an efficient supplement to attenuate reproductive toxicity by environmental toxicants to
ensure healthy sperm production. 相似文献
18.
为探究配体维生素B3(C6H5NO2)、8-羟基喹啉(C9H7NO)及其稀土配合物[RE(C6H4NO2)2(C9H6NO)].2H2O(RE=La、Nd、Sm)对红酵母生物活性的影响,本实验采用平板培养皿法和抑菌圈法测定了上述三元配合物及其配体对野生红酵母和实验红酵母生长活性的影响通过比较分析抑菌圈直径的大小,我们发现8-羟基喹啉(C9H7NO)对红酵母抑制作用较强,而维生素B3没有抑制作用,与稀土(RE=La、Nd、Sm)形成三元配合物后,Sm的三元配合物抑菌能力得到了加强,而Nd和La的三元配合物抑菌能力减弱初步推测Sm配合物可应用于红酵母危害的防治 相似文献
19.
该文建立了同时测定紫花地丁中槲皮素和七叶内酯含量的紫外分光光度法.以槲皮素和七叶内酯混合体系的紫外吸收光谱为基础,采用多元线性回归法（M LR）、偏最小二乘法（PLS）对光谱数据进行解析,得到紫花地丁中槲皮素和七叶内酯含量.用标准加入方法作回收试验,PLS法处理实验数据,测得槲皮素的回收率在85％--95％之间,七叶内酯的回收率在77％--82％之间;MLR法处理实验数据,测得槲皮素的回收率在75％ ～100％之间,七叶内酯的回收率在92％--97％之间.该法具有快速、操作简单、不需分离、重复性好等特点. 相似文献