Modulation of glucose uptake in adipose tissue by nitric oxide-generating compounds

There is increasing evidence that endogenous nitric oxide (NO) influences adipogenesis, lipolysis and insulin-stimulated glucose uptake. We investigated the effect of NO released from S-nitrosoglutathione (GSNO) and S-nitroso N-acetylpenicillamine (SNAP) on basal and insulin-stimulated glucose uptake in adipocytes of normoglycaemic and streptozotocin (STZ)-induced diabetic rats. GSNO and SNAP at 0.2, 0.5, and 1 mM brought about a concentration-dependent increase in basal and insulin-stimulated 2-deoxyglucose uptake in adipocytes of normoglycaemic and STZ-induced diabetic rats. SNAP at 1.0 mM significantly elevated basal 2-deoxyglucose uptake (115.8 ± 10.4%) compared with GSNO at the same concentration (116.1 ± 9.4%;P 0.05) in STZ-induced diabetic rats. Conversely, SNAP at concentrations of 10 mM and 20 mM significantly decreased basal 2-deoxyglucose uptake by 50.0 ± 4.5% and 61.5 ± 7.2% respectively in adipocytes of STZ-induced diabetic rats (P 0.05). GSNO at concentrations of 10 mM and 20 mM also significantly decreased basal 2-deoxyglucose uptake by 50.8 ± 6.4% and 55.2 ± 7.8% respectively in adipocytes of STZ-induced diabetic rats (P 0.05). These observations indicate that NO released from GSNO and SNAP at 1 mM or less stimulates basal and insulin-stimulated glucose uptake, and at concentrations of 10 mM and 20 mM inhibits basal glucose uptake. The additive effect of GSNO or SNAP, and insulin observed in this study could be due to different mechanisms and warrants further investigation.     

Non-cytotoxic silver nanoparticle-polyvinyl alcohol hydrogels with anti-biofilm activity: designed as coatings for endotracheal tube materials

Endotracheal intubation is commonly associated with hospital-acquired infections as the intubation device acts as reservoir for bacterial colonization in the lungs. To reduce the incidence of bacterial colonization on the tubes, hydrogel coatings loaded with antimicrobial agents are gaining popularity. The aim of this study was to incorporate silver nanoparticles (AgNPs) into polyvinyl alcohol (PVA) to form stable hydrogels. Embedding AgNPs into PVA resulted in a decreased elongation at break and an increased tensile strength compared to PVA alone. The Ag release profile varied as a function of the degree of hydrolysis of PVA: the higher degree of hydrolysis demonstrated a lower release rate. Fourier infrared transform spectroscopy demonstrated that AgNPs interacted exclusively with the –OH groups of PVA. AgNP-loaded PVA was non-toxic against human normal bronchial epithelial cells while effective against the attachment of Pseudomonas aeruginosa and Staphylococcus aureus with a greater effect on P. aeruginosa.     

Efficacy of surface-generated nitric oxide against Candida albicans adhesion and biofilm formation

This report details the efficacy of nitric oxide (NO)-releasing xerogel surfaces composed of N-(6-aminohexyl)aminopropyl trimethoxysilane (AHAP3) and isobutyltrimethoxysilane (BTMOS) against Candida albicans adhesion, viability, and biofilm formation. A parallel plate flow cell assay was used to examine the effect of NO on planktonic fungal cells. Nitric oxide fluxes as low as 14 pmol cm^?2 s^?1 were sufficient to reduce fungal adhesion by ～49% over the controls after 90 min. By utilizing a fluorescence live/dead assay and replicate plating, NO flux was determined to reduce fungal viability in a dose-dependent manner. The formation of C. albicans biofilms on NO-releasing xerogel-coated silicon rubber (SiR) coupons was impeded when compared to control (non-NO-releasing) and bare SiR surfaces. The synergistic efficacy of NO and silver sulfadiazine against adhered fungal cells and biofilms is reported with increased killing and biofilm inhibition over NO alone.     

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。     

Cobalt-60 gamma radiation increased the nitric oxide generation in cultured rat vascular smooth muscle cells

Radiation is a promising and new treatment for restenosis following angioplasty. Nitric oxide has been proposed as a potential "anti-restenotic" molecule. We radiated the cultured rat vascular smooth muscle cells with Cobalt-60 gamma radiation at doses of 14 and 25Gy and observed nitrite production, cGMP content, L-arginine uptake, inducible nitric oxide synthase (iNOS) activity, and the gene expression of iNOS. Results showed that radiation at doses of 14 and 25Gy increased cGMP content by 92.4% and 86.4%, respectively. Radiation at the dose of 25Gy increased the iNOS activity and nitrite content, but radiation at the dose of 14Gy had no significant effect on iNOS activity and NO production. Both doses of radiation significantly decreased the L-arginine transport. Radiation at the doses of 14 and 25Gy increased iNOS gene expression significantly, which was consistent with the effect of radiation on iNOS activity. In conclusion, radiation induces the NO generation by up-regulating the iNOS activity.     

老年呼吸机相关性肺炎患者肠道菌群特征及其与疾病的相关性

探讨老年呼吸机相关性肺炎(VAP)患者肠道菌群特征及其与疾病的相关性, 为该类患者的治疗提供参考。

选择2018年1月至2020年1月在该院进行机械通气的患者141例, 根据是否发生VAP分为VAP组(n=67)和非VAP组(n=74), 同时选择同期在我院进行体检的健康者为对照组(n=50)。采用16S rRNA荧光定量PCR法检测3组研究对象肠道双歧杆菌和大肠埃希菌数量, 并计算B/E值。采用流式细胞仪检测T淋巴细胞亚群CD3⁺、CD3⁺CD4⁺、CD3⁺CD8⁺、CD4⁺/CD25⁺、CD8⁺/CD28^-以及CD8⁺/CD28⁺细胞水平。采用改良酶学分光光度法检测血浆D-乳酸水平。采用Pearson相关检验分析VAP组B/E值与免疫功能及血浆D-乳酸的相关性。

VAP组患者肠道双歧杆菌数量、B/E值显著低于非VAP组和对照组, 大肠埃希菌数量显著高于非VAP组和对照组(均P < 0.05);非VAP组和对照组比较差异亦均有统计学意义(均P < 0.05)。VAP组患者CD3⁺、CD3⁺CD4⁺、CD3⁺CD8⁺以及CD8⁺CD28⁺细胞水平显著高于非VAP组和对照组, CD8⁺CD28^-细胞水平显著低于非VAP组和对照组(均P < 0.05);非VAP组和对照组比较差异亦均有统计学意义(均P < 0.05)。VAP组患者血浆D-乳酸水平显著高于非VAP组和对照组, 非VAP组和对照组比较差异亦有统计学意义(均P < 0.05)。Pearson相关检验显示, VAP组患者B/E值与CD3⁺、CD3⁺CD4⁺、CD3⁺CD8⁺、CD8⁺/CD28⁺细胞以及血浆D-乳酸水平呈显著负相关, 与CD8⁺/CD28^-细胞呈显著正相关(均P < 0.05)。

VAP患者存在肠道菌群失衡, 且VAP与肠道菌群失衡存在相关性, 促进肠道菌群平衡有助于VAP的防治。

     

雌性动物生殖系统中的一氧化氮

一氧化氮(nitric oxide,NO)属于无机自由基气体,作为一种特殊的生物传递信号分子,日益受到生命科学各领域的普遍重视。机体内的NO是由三种一氧化氮合酶(nitric oxide synthase,NOS)合成的。NOS在体内的分布极为广泛,几乎遍布机体的每一个系统。研究表明,生殖系统中的NO参与了卵泡的发育和成熟、胚胎的植入、妊娠的维持、分娩等许多生理过程。现就NO在雌性生殖系统中的作用进行阐述。     

Simultaneous detection of NOS-3 protein expression and nitric oxide production using a flow cytometer

Nitric oxide (NO) is involved in the regulation of SMC proliferation during intimal hyperplasia as has been shown by the inhibitory effect on intimal hyperplasia of adenovirus-mediated ceNOS overexpression in injured arteries in pig. Good assays to quantify the NO-producing enzymes, i.e., NO synthases (NOS), are essential to analyze the mechanism of action of NO in this process. We have developed novel flow cytometric assays for the simultaneous detection of NOS-3 protein, using NOS-3 specific antibodies, and NO production using 4,5-diaminofluorescein-diacetate (DAF-2/DA). The presence of NOS-3 protein and NO production is demonstrated on human A549 and HepG2 cells infected with a NOS-3 adenovirus (Ad.NOS-3). A comparative study showed that the flow cytometric assays are equally sensitive as Western blot analysis, the citrulline assay, or the Sievers assay. On human endothelial and SMC, NOS-3 protein and NO production were simultaneously detected with the assays, both under basal conditions and after Ad.NOS-3transduction. Simultaneous analysis of NOS-3 protein and NO production, made possible by the here-described novel flow cytometric assays, is of significant value to those investigating NOS-3 and NO.     

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.     

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。     

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。     

大鼠脑组织中一氧化氮合酶测定

在含有一氧化氮合酶(NOS)底物左族精氨酸(L-Arg), 辅助因子还原性辅酶Ⅱ(NADPH)、四氢生物蝶呤(BH₄)、黄素单核苷酸(FMN), 黄素腺嘌呤二核苷酸(FAD)以及Ca²⁺、钙调蛋白等溶液中加入大鼠脑组织匀浆离心上清液, 组成酶反应体系. 37℃温育80min, 应用N-(1-萘基)-乙二胺、对氨基苯磺酸的重氮、偶氮反应测定酶反应体系中一定时间内NO代谢产物NO^-₂浓度变化, 建立一种简便的NOS活性测定方法. 反应体系最佳pH为7.4, K_m=0.1mmol/L, 体系内NO^-₂生成量与加入样品量之间有良好线性关系(r=0.998). 此方法简单、方便、重复性好, 批内CV为3.69%, 批间CV为5.16%. 10只健康大鼠脑组织中NOS活性为(39.61±7.64)nmol/(min·g).     

Changes occurring in cortical NO release and brain NO-synthases during a paradoxical sleep deprivation and subsequent recovery in the rat

Variations occurring in cortical nitric oxide (NO) release were analysed with a voltametric method in rats (i) placed in control conditions, (ii) while being paradoxical sleep deprived (PSD), or (iii) recovering from a PSD. Activities of neuronal (nNOS) and inducible (iNOS) NO-synthases as well as nNOS expression were also determined in several brain regions. In baseline conditions, circadian variations in nNOS expression and activity were maximal during the dark period and minimal during the light one for all the structures analysed (frontal cortex, pons and medulla). In the same way, cortical NO release occurred through a circadian rhythm exhibiting maxima and minima during dark and light periods, respectively. In the same experimental conditions, iNOS activity did not exhibit time-dependent changes. The correlative changes observed in baseline conditions between NO release, nNOS expression and activity within the frontal cortex were disrupted during PSD and subsequent recovery. Still again, iNOS activity remained unchanged. Results obtained point out that the tight coupling existing in control conditions between nNOS expression-activity and NO release is disrupted by a PSD and remains affected during the subsequent 24 h recovery. Their significance is discussed.     

胰岛素促进血管内皮细胞产生一氧化氮的实验研究

目的：探讨胰岛素对血管内皮细胞增殖、NO产生和NOS基因表达的影响。方法：培养牛主动脉内皮细胞,测定培养上清液中NO氧化产物NO2^－的水平并应用定量RT－PCR技术检测内皮细胞NOS mRNA的表达水平。结果：①胰岛素对大血管内皮细胞无细胞毒作用,也不影响细胞增殖;②在1－15μg/ml浓度范围内,胰岛素加强内皮细胞释放NO,且呈剂量依赖的方式,NOS特异性抑制剂L－NAME可阻抑之;③胰岛素轻度增加NOS mRNA表达水平,但无统计学意义。结论：胰岛素既不影响大血管内皮细胞增殖,也不影响内皮细胞NOS mRNA表达水平,但以剂量依赖的方式加强内皮细胞产生NO,推测其诱导NO产生的机制可能是通过酶活性的诱导,加速NO的合成。