一氧化氮在心血管活动调控中的作用

一氧化氮是20年来医学研究的热点之一，一氧化氮在心血管活动调控和许多心血管疾病如高血压、动脉粥样硬化、器官缺血再灌注损伤的病理机制中都有重要作用．其作用即有有利的一方面，又有有害的一方面．在一氧化氮合酶作用下产生的一氧化氮对机体具有保护作用。另一方面，受细菌内毒素或细胞因子等诱导，一氧化氮合酶表达上调并产生大量一氧化氮引起细胞损伤和循环衰竭．目前有许多临床实验正在评价一氧化氮在心血管疾病中的作用．     

一氧化氮的生物学作用研究

一氧化氮具有广泛的生理功能,对血管活动、胃肠运动具有调节作用,而且参与了神经信息的传递,与机体免疫也有密切关系。一氧化氮过量释放可导致神经毒性。     

一氧化氮、一氧化氮合酶、血管内皮生长因子与流产(讲座)

一氧化氮广泛存在于各组织器官中，除具有细胞毒性、加重脑缺血损伤、参与神经内分泌活动及抑制血小板聚集外，还诱导细胞凋亡以及在胚胎早期发生、发展中起作用。     

一类隐马尔可夫模型的若干极限性质

假定隐藏的马尔可夫链为非齐次，研究隐非齐次马尔可夫模型的一些强极限定理．首先在引理中得出了隐非齐次马尔可夫模型的一些性质，从而导出了隐非齐次马尔可夫模型的三元函数一类平均值的强极限定理．作为定理的推论，得到了隐非齐次马尔可夫模型状态出现频率的一类强极限定理．隐马尔可夫模型可应用于弱相依随机变量的建模上，也可用作研究发音过程、神经生理学与生物遗传等方面的工具．     

基于三值语义的非单调逻辑

本文给出一种三值非单调逻辑形式，它一方面可推广标准非单调逻辑到三值情形，另一方面它能捕捉各种非单调逻辑作为特殊形式，特别地，我们证明了三值非单调逻辑与模态非单调逻辑具有密切的关系．     

神经系统中的重要信使分子——NO

体内的ＮＯ是在ＮＯ合成酶催化下由精氨酸分解产生的。作为一种气体分子在神经系统中具有细胞间信使的作用。它主要通过谷氨酸递质的ＮＭＤＡ受体激活而生成，引起靶细胞ｃＧＭＰ升高，产生相应的生理效应。它介导了兴奋性传导，对小脑、海马等神经元上突触可触性和长时程增强作用产生重要影响。但ＮＯ过量产生或释放时可导致神经毒性。     

脑室微量注射兴奋性神经递质谷氨酸对消炎痛－胃溃疡的抑制效应

脑室微量注射兴奋性神经递质谷氨酸（Ｇｌｕ，１－７ｎｍｏｌ）可显著抑制小白鼠消炎痛－胃溃疡的发生（Ｐ＜０．０１），并呈现明显的剂量－效应依赖关系（ｒ＝－０．９３６，Ｐ＜０．０２）。腹腔注射Ｇｌｕ（１００ｎｍｏｌ）或尾静脉注射Ｇｌｕ（１００ｎｍｏｌ）对消炎痛－胃溃疡均无影响。胆碱能神经Ｍ受体阻断剂阿托品（ｓ．ｃ．０．０２ｍｇ·ｋｇ（－１））使溃疡明显加重，但它不能阻断Ｇｌｕ对消炎痛－胃溃疡的抑制效应。肾上腺素能神经α受体阻断剂酚妥拉明（ｉ．ｍ．２．５ｍｇ·ｋｇ（－１））对消炎痛－胃溃疡无影响，并且不能阻断Ｇｌｕ的抑制效应。以上结果提示，外源性Ｇｌｕ并非通过外周而是通过中枢特异性机制来抑制消炎痛－胃溃疡的。可能在消炎痛－胃溃疡发生中，边走神经紧张性活动对胃粘膜具有保护作用，而交感神经紧张性活动无作用。但Ｇｌｕ在中枢对消炎痛－胃溃疡的作用既不通过迷走神经，也不通过交感神经，而可能通过其它途径，如神经内分泌、血液循环等来抑制消炎痛－胃溃疡。     

一氧化氮的生物学意义及应用前景

一氧化氮既是气体 ,也是一个自由基 ,是机体内一种作用广泛而性质独特的信号分子 在不同的器官、不同生理或病理状态下可发挥或利或害的双重作用 一氧化氮是心血管系统最关键的信号分子 ,除此之外 ,它还是神经系统的信号分子 ,抗感染的武器 ,血压的调节因子和血流进入各种器官的守门人 但如果其生成不足或过量 ,则呈现病理毒素的反应 ,引起免疫功能异常 ,神经毒、心血管、呼吸、消化及泌尿系统疾患等     

实时监测体内的分子活动

<正>美国麻省理工学院的研究人员近日开发出一种碳纳米管传感器,把它植入皮下之后,可全年实时监测活体动物体内的分子活动,如炎症反应中产生一氧化氮(NO)的过程,或监测血糖及胰岛素水平,而无需再像传统方式那样采血检验。该研究结果发表在《自然·纳米技术》(Nature nanotechnology)上。一氧化氮是活细胞中最重要的信号分子,具有在大脑内运送信息及调整免疫系统的功能。在许多癌细胞中,一氧化氮水平是波动的,但很少有人知道它在健康细胞和癌细胞内的作用方式。     

色素上皮源性因子——一种新的神经营养和保护因子

PEDF是最近发现的一种神经营养因子，在许多组织均由表达。它具有强大的营养和保护神经作用。已有研究显示其作用机制主要涉及N-端结构域，改变细胞内钙离子，影响其它因子和胶质细胞而发挥作用等等。它对于神经疾病的治疗可能具有很大的潜力。     

Nitric oxide release from a single cell measured in situ by a porphyrinic-based microsensor.

Nitric oxide is an important bioregulatory molecule, being responsible, for example, for activity of endothelium-derived relaxing factor (EDRF). Acute hypertension, diabetes, ischaemia and atherosclerosis are associated with abnormalities of EDRF. Nitric oxide is thought to be a retrograde messenger in the central nervous system. The technology is not yet available for rapid detection of NO released by a single cell in the presence of oxygen and/or nitrite, so the release, distribution and reactivity of endogenous NO in biological systems cannot be analysed. Here we describe a porphyrinic microsensor that we have developed and applied to monitoring NO release in a microsystem. We selectively measured in situ the NO released from a single cell with a response time of less than 10 ms. The microsensor consists of p-type semiconducting polymeric porphyrin and a cationic exchanger (Nafion) deposited on a thermally sharpened carbon fibre with a tip diameter of approximately 0.5 microns. The microsensor, which can be operated in either the amperometric or voltammetric mode, is characterized by a linear response up to 300 microM and a detection limit of 10 nM. Nitric oxide at the level of 10(-20) mols can be detected in a single cell.     

对一氧化氮作用的新认识

一氧化氮作为一种新的信使分子和生物调质,在生物体中发挥着广泛的生理学、病理学和药理学作用.结合NO的性质,综述了NO在生物体中的作用,重新认识了NO的生物学功能.     

下丘脑室旁核NOS／NO系统对心血管活动的调节（综述）

下丘脑室旁核（PVN）是重要的心血管活动调节中枢。PVN分布有一氧化氮（NOS）神经元,合成并释放一氧化氮（NO）。NO通过抑制各级交感神经中枢,以及影响神经内分泌活动,对心血管活动进行调节。     

一氧化氮治疗肿瘤的研究进展

一氧化氮（NO）是一种半衰期很短的气体分子，对细胞膜具有高穿透性，能在人体内传递重要信息，并具有调节细胞的功能.NO气体分子既能维持正常细胞的生理功能和活性，又能选择性地快速耗尽肿瘤细胞的能量，诱导肿瘤细胞凋亡.研究表明：NO可以通过多种机制实现肿瘤治疗.已有一些NO供体药物表现出良好的抗肿瘤活性，精确控制NO在肿瘤部位的释放，可杀死肿瘤细胞.因此，NO气体疗法作为一种肿瘤治疗策略具有一定的应用前景.文章简述了NO的生理学特性和几种典型的NO供体，以及释放NO的生物材料在生物医学领域的应用进展.     

Nitric oxide mediates the fungal elicitor-induced Taxol biosynthesis of Taxus chinensis suspension cells through the reactive oxygen species-dependent and -independent signal pathways

Taxol (paclitaxel, NSC-125973), a secondary me- tabolite of the Taxus species, has been recognized as one of the best anticancer drugs emerging in the last decade[1]. The production of Taxol by various Taxus spp. cells in culture has been one of the most …     

Nitric oxide in female reproductive system

Nitric oxide (NO), synthesized from L-arginine and oxygen by a family of enzymes known as nitric oxide synthase (NOS), is an effective and intercellular signal transduction molecule, and is ubiquitously present in vertebrates. To date, there are three distinct isoforms of NOS: neural NOS (nNOS), inducible NOS (iNOS), and endothelial NOS (eNOS). Among them, eNOS and nNOS, also called constitutive isoforms (cNOS), require calcium for activity, and are expressed constitutively in the physiological condition. The third isoforms, iNOS, whose activity is not dependent on calcium, are produced only in response to some stimulus, including cytokines and immune stimulating factors, etc.[1].     

Regulation between nitric oxide and MAPK signal transduction in mammals

Nitric oxide (NO) is an important biological messenger in the regulation of tissue homeostasis. It exhibits a wide range of effects during physiological and pathophysiological processes. Typical beneficial properties of NO include the regulation of vascular tone,the protection of cells against apoptosis, the modulation of immune responses, and the killing of microbial pathogens. On the other hand,NO may cause severe vasodilation and myocardial depression during bacterial sepsis or act as a cytotoxic and tissue-damaging molecule in autoimmune diseases. Mitogen-activated protein kinase (MAPK) is a family of serine/threonine protein kinases that are widely distributed in mammalian cells. MAPK cascade plays pivotal roles in gene expression, cell proliferation, differentiation, neuronal survival and programmed cell death under a variety of experimental conditions. MAPKs transduce the signal for the cellular response to extracellular stresses or stimuli. The relation between them, however, has never been reviewed. Based on our researches and other reports in the field, we review their reciprocal regulatory functions.     

白细胞介素-1的结构、来源、分布、功能及其与疾病的关系

白细胞介素-1(IL-1)不仅作为一种重要的细胞因子,是体内调节免疫和炎症反应的中心介质,而且它也作为神经递质或生长因子参与了机体多个系统的病理生理活动,其生物学作用非常广泛.近年来,随着对神经系统、免疫系统和内分泌系统之间相互作用研究的日益深入,IL-1在各系统中的作用与机制也得到了相应的证实,并为一些临床疾病的诊治提供了有力依据.文章针对IL-1作为脑源性白介素在中枢神经系统的病理生理功能进行了研究.     

基于二氟荧光素内酰胺的一氧化氮分子荧光探针的合成及应用

合成了基于二氟荧光素内酰胺开环反应的一氧化氮分子荧光探针并对其结构进行了表征。二氟荧光素内酰胺本身无荧光,当与NO反应后开环水解生成二氟荧光素,在λex=484nm光激发下产生荧光且最大发射波长λem=514nm。在PH〉4．8的体系中二氟荧光素内酰胺与NO反应后荧光强度达最大且稳定。在H2O2、·OH、O2-、NO2-、ONOO-存在下,荧光探针对NO表现出很高的选择性。以NOC13为NO释放剂,荧光强度随NOC13浓度的增加而增大,可实现对NO的直接检测。     

Vasorelaxant properties of the endothelium-derived relaxing factor more closely resemble S-nitrosocysteine than nitric oxide

Studies of cultured bovine aortic endothelial cells using quantitative chemiluminescence techniques have shown that the amount of nitric oxide released under basal conditions, or in response to either bradykinin or the calcium ionophore A23187 is insufficient to account for the vasorelaxant activities of the endothelium-derived relaxing factor (EDRF) derived from the same source. This observation contradicts previous suggestions that nitric oxide and EDRF are the same compound, but may be explained if EDRF is a compound that contains nitric oxide within its structure but is a much more potent vasodilator than nitric oxide. Such a molecule could be one of several nitrosothiols which may yield nitric oxide after a one-electron reduction. The present experiments were carried out to test the possibility that the biological activities of the endothelium-derived relaxing factor might more closely resemble those of one of these compounds, S-nitrosocysteine, than nitric oxide. Nitric oxide release from cultured bovine aortic endothelial cells was detected by chemiluminescence and bioassay experiments compared the vasodilator potencies of nitric oxide, S-nitrosocysteine, and EDRF. The results suggest that EDRF is much more likely to be a nitrosylated compound such as a nitrosothiol than authentic nitric oxide.