鞘内注射MK-801对炎性痛大鼠海马NOS表达及NO含量的影响

目的：观察鞘内给予N-甲基-D-天门冬氨酸（NMDA）受体拮抗剂MK-801对足底注射甲醛诱导的自发痛反应和海马一氧化氮合酶（NOS）表达及一氧化氮（N0）含量的影响,探讨炎性痛诱导海马NO产生增多的机制。方法：通过观察舔足反射时间反映大鼠自发痛程度;采用NADPH—d组织化学法测定大鼠海马NOS表达;硝酸还原酶法测定海马组织NO含量。结果：足底注射甲醛后动物即出现舔、咬、摇动注射侧脚掌等自发痛相关表现,预先鞘内注射MK-801可使大鼠第二时相自发病程度显著降低,但对第一时相痛反应程度无明显影响。注射甲醛后12h时,海马CA1、CA2～3区及DG区NOS阳性细胞数目、阳性细胞染色深度均显著增加,海马组织NO含量显著增加;预先鞘内注射MK-801,可使甲醛炎性痛大鼠海马各区NOS阳性细胞数目明显减少,阳性细胞染色深度明显变浅,海马NO含量明显降低。结论：鞘内注射MK-801可逆转甲醛炎性痛诱导的海马NOS表达及NO产生的增加,表明甲醛炎性痛诱导的海马NO产生增加主要是由于伤害性信息传入所引起。     

CGRP受体拮抗剂CGRP8-37对甲醛炎性痛大鼠自发痛反应及脊髓后角NOS表达和NO含量的影响

目的:探讨CGRP受体拮抗剂CGRP8-37对甲醛炎性痛大鼠自发痛反应及脊髓后角NOS表达和NO含量的影响.方法:大鼠足底注射甲醛制造炎性痛模型;计数缩足反射次数反映自发痛程度;NADPH-d组织化学法观察脊髓后角NOS表达;硝酸还原酶法测定NO-3/NO-2含量以反映NO含量.结果:足底注射甲醛后,动物出现自发痛反应行为.足底注射甲醛后24 h,双侧脊髓后角NOS表达及NO含量明显增加.预先鞘内注射CGRP8-37可使甲醛诱导的自发性缩足反射次数明显减少,并可明显抑制甲醛炎性痛诱导的脊髓后角NOS表达及NO含量的增加.结论:甲醛炎性痛时,脊髓后角CGRP受体激活可促进NOS活性表达及NO的产生.     

PKC激动剂佛波醇酯诱导大鼠伤害性感受并促进脊髓NO产生

目的:观察PKC激动剂PMA诱导大鼠伤害性感受作用及对脊髓NOS表达和NO生成的影响.方法:采用行为学方法观察大鼠痛反应;热甩尾法测定大鼠痛阈变化;采用NADPH-d组织化学法和硝酸还原酶法分别测定大鼠脊髓内NOS表达和NO含量.结果:鞘内注射PMA后,大鼠出现伤害性感受反应及痛阈降低,脊髓后角浅层和中央管周围灰质内NOS阳性细胞数目、阳性细胞胞体及突起的染色深度明显增加,脊髓NO含量亦明显增加.给予PKC选择性抑制剂CH预处理可阻断鞘内注射PMA诱导的上述改变.结论:脊髓神经元内PKC激活可诱导大鼠产生伤害性感受及热痛觉过敏,并可促进NO产生,其对NO产生的促进作用可能是其诱导痛觉过敏产生的机制之一.     

甲醛炎性痛诱导大鼠海马神经元凋亡

目的：观察甲醛炎性痛是否可诱导大鼠海马神经元凋亡。方法：采用行为学方法观察大鼠自发痛反应,流式细胞术检测海马神经元凋亡率,免疫组织化学法检测海马神经元p53蛋白的表达。结果：与正常对照组相比,大鼠足底皮下注射甲醛后海马神经元凋亡率显著增高,海马各区p53蛋白表达明显增加,二者均于注射甲醛后3d达高峰;足底两次注射甲醛和一次注射甲醛组比较,大鼠自发痛反应增强,并且海马神经元凋亡率进一步增加。结论：甲醛炎性痛可诱导大鼠海马神经元凋亡,这种改变具有一定的时程特征;海马神经元凋亡率与疼痛强度有关;p53蛋白的表达增加可能参与了伤害性信息传入对神经元凋亡的诱导。     

鞘内注射神经激肽-1受体激动剂Sar-SP增强大鼠脊髓一氧化氮合酶表达和一氧化氮生成

探讨P物质(substance P,SP)对脊髓一氧化氮合酶(nitric oxide synthase,NOS)表达和一氧化氮(nitric oxide,NO)生成的影响。实验用热甩尾法测定大鼠痛阈的变化,分别应用NADPH-d组织化学法和硝酸还原法测定大鼠脊髓内NOS表达和NO生成的变化。结果显示,鞘内注射神经激肽-1受体(neurokinin-1 receptor,NK-1)激动剂[Sar^9,Met(O2)^11]-substance P(Sar-SP)可使大鼠痛阈降低,脊髓后角浅层和中央管周围灰质内NOS表达增强,脊髓腰膨大部位NO生成增多;预先鞘内注射非选择性NK-1受体拮抗剂[D—Arg^1,D-Trp^7,9,Leu^11]-substance P(spantide)可抑制上述变化。结果表明,SP可促进脊髓内NOS表达和NO生成。     

中缝背核微量注射L-N-硝基精氨酸甲酯抑制大鼠乙状结肠痛

用Fos免疫组织化学、烟酰胺腺嘌呤二核苷酸磷酸黄递酶(nicotinamide adenine dinucleotide phosphate—di—aphorase,NADPH-d)组织化学及微量注射技术,观察大鼠乙状结肠注射甲醛(5％)诱发的大鼠乙状结肠炎性痛过程中中缝背核一氧化氮合酶(nitric oxide synthase,NOS)神经元的变化,同时观察中缝背核微量注射L-N-硝基精氨酸甲酯(LNAME)对乙状结肠痛的调控作用。结果表明,(1)乙状结肠注射甲醛后,大鼠出现明显的内脏痛反应,中缝背核NOS神经元表达明显增多,中缝背核内出现大量Fos蛋白,在整个中缝背核内均有分布,并且出现Fos／NOS双标神经元,约占中缝背核NOS神经元总数的8％,与生理盐水对照组相比差异有显著性;(2)中缝背核注射L-NAME后,可以明显减少乙状结肠炎性痛大鼠的疼痛学评分及脊髓相应节段Fos蛋白。上述结果提示,中缝背核NOS神经元参与调控大鼠乙状结肠痛,NO在中缝背核促进内脏伤害性信息的传递。     

NOS抑制剂对甲醛炎性痛诱导的大鼠痛反应及脊髓神经元凋亡的影响

目的：观察甲醛炎性痛是否可诱导脊髓神经元凋亡以及一氧化氮（NO）对甲醛炎性痛诱导的大鼠痛反应以及脊髓神经元凋亡的影响。方法：采用行为学方法观察大鼠自发痛反应,流式细胞术检测脊髓神经元凋亡率。结果：与正常大鼠比较,甲醛炎性痛可诱导大鼠脊髓神经元凋亡率明显增加,于注射甲醛后3d时最为明显。预先鞘内注射NOS抑制剂L-NAME可剂量依赖性抑制足底注射甲醛诱导的大鼠第一相和第二相痛反应,并可剂量依赖性抑制足底注射甲醛诱导的脊髓神经元凋亡过程;正常大鼠鞘内注射L-Arg也可诱发出伤害性反应和脊髓神经元凋亡。结论：甲醛炎性痛可诱导脊髓神经元发生凋亡,于注射甲醛后3d神经元凋亡最为明显;炎性痛诱导的NO产生增多促进了脊髓伤害性信息传递过程,并在炎性痛诱导的脊髓神经元凋亡过程中发挥促进作用。     

大鼠脑缺血／再灌注损伤中一氧化氮和一氧化氮合酶的变化

目的:探讨脑缺血/再灌注损伤中脑组织一氧化氮和一氧化氮合酶的变化.方法:用线栓法建立大脑中动脉梗死(MCAO)模型,观察局灶性脑缺血30 min再灌注30 min、1 h、3 h、 6 h、12 h、24 h、48 h 、72 h、96 h、168 h NO含量和NOS活性的变化.结果:脑缺血/再灌注过程中NO含量和NOS活性呈"双峰样"改变.缺血/再灌注30 min后NO含量和NOS活性升高,再灌注3 h时NO含量和NOS活性下降,再灌注6 h、12 h、24 h、48 h 、72 h NO含量和NOS活性再次显著升高,与再灌注72 h达峰值.结论:NO和NOS通过多种途径参与了脑缺血/再灌注损伤的病理过程.     

MK—801降低炎性痛在鼠脊髓NOS表达和NO含量

用NADPH-d组织化学法,观察鞘内注射NMDA受体拮抗剂MK-801对大鼠右后掌皮下注射甲醛诱发的炎症性痛及痛过敏过程中脊髓后角一氧化氮合酶(NOS)表达的影响,同时测定一氧化氮(NO)代谢终产物     

牛磺酸对失血性休克复苏家兔血浆和心肌NOS活性影响

目的:探讨牛磺酸对失血性休克复苏后血浆和心肌一氧化氮合酶(NOS)活性、一氧化氮(NO)含量变化的影响.方法:新西兰种兔24只随机分为3组(n=8):对照组、休克组、牛磺酸治疗组.采用失血性休克复苏动物模型.连续观察休克前、休克1.5 h、复苏后1 h、2 h、3 h血浆一氧化氮合酶(NOS)活性、一氧化氮代谢产物(NO-2/NO-3)含量、乳酸脱氢酶(LDH)活性的动态变化.测定复苏后3 h心肌一氧化氮合酶(NOS)活性、一氧化氮代谢产物(NO-2/NO-3)含量的变化,并常规留取心肌标本观察形态学改变.结果:①休克组复苏后各时限血浆NOS活性、NO-2/NO-3含量、LDH活性显著高于休克前及休克1.5 h;②休克组复苏后3 h心肌NOS活性、NO-2/NO-3含量显著高于对照组,心肌出现明显水肿和脂肪变性;③牛磺酸(40 mg·kg-1 iv)可显著缓解上述变化.结论:失血性休克复苏后NOS的激活和NO的大量释放,可能介导了休克复苏所致心肌损伤,牛磺酸可减少NO的生成使心肌损伤减轻.     

昆虫一氧化氮及其合酶的研究进展

一氧化氮作为一种重要的信息分子 ,参与调节昆虫嗅觉、视觉、机械感受、发育、机体防御及学习行为。该文从生理、生化、形态定位以及信号转导几方面综述了有关昆虫一氧化氮及其合酶的最新研究进展。     

白细胞介素—10对血管一氧化氮／一氧化氮合酶系统的影响

为探讨抗炎因子－－白细胞介素－10（IL－10）对大鼠主动脉一氧化氮（NO）／一氧化氮合酶（NOS）系统的影响,应用Griess试剂、^3H－瓜氨酸生成及蛋白免疫印迹杂交等方法,测定IL－10孵育对血管NO释放、NOS活性及表达的影响。结果发现细菌脂多糖（LPS）呈浓度领带性地激活诱导型NOS（iNOS）,促进NO生成。IL－10（10^-10-10^-8g/ml）呈浓度依赖性地上调内皮型NOS（eNOS）蛋白表达及其活性,但对iNOS活性及表达无明显影响,IL－10（10^-9-10^-8g/ml）显著抑制10μg/ml LPS诱导的NO生成和iNOS激活;而高浓度IL－10（10^-7g/ml）则上调iNOS的活性,对eNOS蛋白的表达知活性无明显影响。因此IL－10对NO／NOS系统具有双重影响,一方面可抑制炎症介质诱发的作为炎性物质的iNOS的表达及激活,另一方面可上调内皮源扩血管物质NO的释放。     

The language of nitric oxide signalling

Nitric oxide (NO) has recently joined the select circle of the ubiquitous molecules of plant signalling networks. Indeed, the last decade has produced a tremendous amount of data that evidence the diversity of physiological situations in which NO is involved in plants and the complexity of NO biology. These data also underline our difficulties in providing simple answers to the cardinal questions of where NO comes from and how the NO message is converted into a physiological response. The identification of NO primary targets and NO-regulated genes provides new opportunities to connect NO biochemistry and NO biology. This review summarises our current understanding of NO signalling, from the generation of the NO message to its execution into a cellular response. The review particularly considers whether and how NO may be responsible for specific signalling in different physiological processes.     

NO在脊髓痛觉传递过程中的作用

一氧化氮(nitric oxide,NO)是神经元细胞内一种新型的神经递质,它参与多种生命活动,包括脊髓水平的伤害性信息传递过程。研究NO在伤害性信息传递过程中的作用及其机制,有利于阐明痛觉生理和发现疼痛治疗的新手段。本文将NO在慢性痛脊髓伤害性信息传递中的作用及其机制的相关研究进展作一综述。     

一氧化氮在炎性疼痛中的作用

一氧化氮（nitric oxide,NO）是细胞内重要的信使分子和神经递质,它参与多种生命活动,包括炎性疼痛.NO对炎性疼痛的发展和维持起到了重要的作用.研究NO在疼痛中所起到的作用及其机制有利于阐明痛觉生理和发现疼痛治疗的新手段.目前研究表明,脊髓水平NO参与炎性疼痛调制的可能机制主要有NO/cGMP途径、参与调控即刻早期基因、与其他神经递质的协同作用.另外研究表明,3种类型的一氧化氮合酶（nitric oxide synthases,NOS）在炎性疼痛过程中被激活或者有不同程度的增强表达.     

Activation of pig oocytes using nitric oxide donors

Nitric oxide (NO) plays an important role in intracellular signaling, but its role during the activation of mammalian oocytes is little understood. In our study, in vitro matured pig oocytes were cultured with NO-donors-S-nitroso-N-acetylpenicillamine (SNAP) or sodium nitropruside (SNP). These treatments were able to induce parthenogenetic activation of pig oocytes matured in vitro. The specificity of this effect was confirmed by the activation of oocytes by exogenous endothelial nitric oxide synthase (eNOS) microinjected in the oocyte with its activator calmodulin. Relatively long exposure (10 hr) is needed for activation of pig oocytes with 2.0 mM SNAP. An active NOS is necessary for the NO-dependent activation of pig oocytes because NOS inhibitors L-NMMA or L-NAME are able to inhibit activation of oocytes with NO-donor SNAP. On the basis of our data, we conclude that the NO-dependent activating stimulus seems inadequate because it did not induce the exocytosis of cortical granules. Also, the cleavage of parthenogenetic embryos was very low, and embryos did not develop beyond the stage of eight blastomeres.     

Production of nitric oxide under Ultraviolet-B irradiation is mediated by hydrogen peroxide through activation of nitric oxide synthase

Excised leaves of kidney bean (Phaseolus vulgaris) were used to investigate the mechanism of NO generation under UV-B stress. We showed that two signaling molecules, NO and H₂O₂, were produced in the irradiated leaves. NO release was blocked by LNNA, an inhibitor of NOS. Application of CAT (EC 1.11.1.6) not only effectively eliminated H₂O₂ in the leaves, but also inhibited the activity of NOS and the emission of NO. In contrast, treatment with exogenous H₂O₂ increased both of those events. Therefore, we suggest that, under UV-B stress, NO production is mediated by H₂O₂ through greater NOS activity.     

Interaction of caveolin-1, nitric oxide, and nitric oxide synthases in hypoxic human SK-N-MC neuroblastoma cells

Neuroblastoma cells are capable of hypoxic adaptation, but the mechanisms involved are not fully understood. We hypothesized that caveolin-1 (cav-1), a plasma membrane signal molecule, might play a role in protecting neuroblastoma cells from oxidative injury by modulating nitric oxide (NO) production. We investigated the alterations of cav-1, cav-2, nitric oxide synthases (NOS), and NO levels in human SK-N-MC neuroblastoma cells exposed to hypoxia with 2% [O2]. The major discoveries include: (i) cav-1 but not cav-2 was up-regulated in the cells exposed to 15 h of hypoxia; (ii) NO donor 1-[N, N-di-(2-aminoethyl) amino] diazen-1-ium-1, 2-diolate up-regulated the expression of cav-1, whereas the non-selective NOS inhibitor N(G)-nitro-L-arginine methyl ester and inducible NOS (iNOS) inhibitor 1400W each abolished the increase in cav-1 expression in the hypoxic SK-N-MC cells. These results suggest that iNOS-induced NO production contributes to the up-regulation of cav-1 in the hypoxic SK-N-MC cells. Furthermore, we studied the roles played by cav-1 in regulating NO, NOS, and apoptotic cell death in the SK-N-MC cells subjected to 15 h of hypoxic treatment. Both cav-1 transfection and cav-1 scaffolding domain peptide abolished the induction of iNOS, reduced the production of NO, and reduced the rates of apoptotic cell death in the hypoxic SK-N-MC cells. These results suggest that increased expression of cav-1 in response to hypoxic stimulation could prevent oxidative injury induced by reactive oxygen species. The interactions of cav-1, NO, and NOS could be an important signal pathway in protecting the neuroblastoma cells from oxidative injury, contributing to the hypoxic tolerance of neuroblastoma cells.     

诱导型一氧化氮合酶介导β淀粉样蛋白在体神经毒性

目的：探讨一氧化氮合酶（NOS）及一氧化氮（NO）在β淀粉样蛋白（Aβ）神经毒性和Alzheimer病（AD）发病机制中的介导作用。方法：应用行为学及病理学方法,观察海马注射Aβ1－40对大鼠Y迷宫学习记忆的影响及对局部神经元的损伤作用;观察特异性诱导型一氧化氮合酶（iNOS)抑制剂胍氢酶（AG）及特异性神经元型一氧化氮合酶(nNOS)抑制剂7－硝基吲哚（7－NI）腹腔注射对海马内注射Aβ1－40神经毒性的干预,结果：海马注射Aβ1－40后,大鼠Y迷宫学习记忆能力及海马局部神经元明显受损,特异性iNOS抑制剂AG能够阻止Aβ1－40海马注射对大鼠学习记忆和局部神经元的损伤作用,而特异性nNOS抑制剂7－NI无此干预效应。结论：iNOS/NO参与了在体条件下对Aβ神经毒性的介导,在AD发病机制中具有重要作用。     

Processes regulating nitric oxide emissions from soils

Nitric oxide (NO) is a reactive gas that plays an important role in atmospheric chemistry by influencing the production and destruction of ozone and thereby the oxidizing capacity of the atmosphere. NO also contributes by its oxidation products to the formation of acid rain. The major sources of NO in the atmosphere are anthropogenic emissions (from combustion of fossil fuels) and biogenic emission from soils. NO is both produced and consumed in soils as a result of biotic and abiotic processes. The main processes involved are microbial nitrification and denitrification, and chemodenitrification. Thus, the net result is complex and dependent on several factors such as nitrogen availability, organic matter content, oxygen status, soil moisture, pH and temperature. This paper reviews recent knowledge on processes forming NO in soils and the factors controlling its emission to the atmosphere. Schemes for simulating these processes are described, and the results are discussed with the purpose of scaling up to global emission.