细胞因子促进人BT325胶质瘤细胞产生一氧化氮

目的：观察脂多糖及一些前炎性细胞因子对体外培养的星形交质细胞产生一氧化氮（ＮＯ）的影响。方法：Ｇｉｒｅｓｓ法检测细胞培养上清中ＮＯ２＾－含量。结果：体外培养４ｈ时人ＢＴ３２５星形胶质瘤细胞开始产生Ｎ）,１２ｈ达高峰（１５．０－１７．５μｍｏｌ．Ｌ＾－１）并持续至７２ｈＬＰＳ１ｍｇ。Ｌ＾－１,ＩＦＮ－γ１００ｋＵ．Ｌ＾－１,ＴＮＦα １００ｋＵ．Ｌ＾－１,ＩＬ－１及ＩＬ－２ＮＯ〉以ＴＮＦ－α,ＩＬ－     

脂多糖刺激体外大鼠小胶质细胞产生细胞肽和一氧化氮

AIM: To study the characterization of interleukin (IL)-1, IL-2, tumor necrosis factor-alpha (TNF-alpha), and nitric oxide (NO) production in microglia stimulated with lipopolysaccharides (LPS). METHODS: Primary cultured neonatal rat microglia were incubated with LPS (0-10 mg.L-1) for 0-72 h. The supernatants and lysates were collected. IL-1, IL-2, and TNF-alpha were assayed by mouse thymocyte proliferation, mouse spleen cell proliferation, and 1929 cytotoxity, respectively. NO was assayed by Griess reaction. RESULTS: Extracellular IL-1, TNF-alpha, and NO production reached peak levels at LPS 1 mg.L-1. Intracellular IL-1 production reached its peak level at LPS 100 micrograms.L-1. Intracellular TNF-alpha level was very low. IL-1, TNF-alpha, and NO activities were detected at 1, 4, and 8 h, after the cells were stimulated with LPS. IL-1 got to its peak value at 8 h, TNF-alpha, and NO reached the highest levels at 24 h. However, IL-2 activity was not detected after the microglia were stimulated with LPS 0-10 mg.L-1 during the incubation period. CONCLUSION: Rat microglia stimulated with LPS in vitro produced proinflammatory cytokines and NO.     

Cytokine and nitric oxide production by rat microglia stimulated with lipopolysaccharides in vitro

目的：研究ＬＰＳ刺激体外培养的新生大鼠小胶质细胞产生ＩＬ１，ＩＬ２，ＴＮＦα和ＮＯ的特征．方法：小胶质细胞与ＬＰＳ（０－１０ｍｇ·Ｌ－１）孵育０－７２ｈ，分别测定细胞外和细胞内的ＩＬ１，ＩＬ２和ＴＮＦα的生物活性和细胞外ＮＯ水平．结果：ＩＬ１，ＴＮＦα和ＮＯ分别在ＬＰＳ刺激后１，４，和８ｈ检测到，并在８，２４和２４ｈ达到峰值．ＬＰＳ１ｍｇ·Ｌ－１刺激细胞外ＩＬ１，ＴＮＦα和ＮＯ的产生最高，但细胞内ＴＮＦα水平极低，ＬＰＳ未能刺激ＩＬ２产生．结论：体外ＬＰＳ刺激大鼠小胶质细胞产生大量炎性细胞肽和ＮＯ．     

银杏内酯A和B及石杉碱甲抑制大鼠C6及人BT325胶质瘤细胞产生一氧化氮(英文)

目的:观察银杏内酯A(Gin A),银杏内酯B(GinB)及石杉碱甲(Hup A)对体外培养的星形细胞产生一氧化氮(NO)的影响。方法:Griess法检测细胞培养上清中NO_2~-含量。结果:HupA0.001-100μmol·L~(-1)明显抑制大鼠C6细胞产生NO,该抑制作用呈浓度及时间依赖性,在0.001-10μmol·L~(-1)范围作用24h,Gin A和Gin B均浓度依赖性地抑制C6细胞产生NO。在0.01-10μmol·L~(-1)范围作用24h,Hup A,Gin A和Gin B均浓度依赖性地抑制人BT325细胞产生NO。结论:Hup A,GinA和Gin B抑制大鼠及人星形细胞产生NO。     

晚期糖基化终产物诱导星型胶质细胞活化：细胞因子分泌与一氧化氮释放

目的:研究两种体外温育的晚期糖基化终产物(AGE)是否可以诱导星型胶质细胞分泌白介素-1β和肿瘤坏死因子α,并导致氧应激增加、一氧化氮释放.方法:RT-PCR技术检测两种细胞因子水平及AGE受体(RAGE)存在与否;DTNB反应测量还原型谷胱甘肽的水平;利用Griess试剂测量一氧化氮含量.结果:AGE 1 g/L(尤其是半乳精温育产物)作用72小时后使星型胶质细胞培养上清和细胞裂解物的细胞因子含量显著升高.且呈剂量依赖性.半定量RT-PCR证明两种细胞因子的变化是由于其转录水平增加所致.AGE还可导致星型胶质细胞内还原性谷胱甘肽减少,一氧化氮释放.RAGE存在于此类星型胶质细胞中.结论:AGE可诱导星型胶质细胞分泌炎性因于白介素-1β和肿瘤坏死因子α,并升高氧应激水平,这至少部分解释了AGE在神经变性性疾病如阿尔采默病和帕金森氏病以及脑衰老中的负性作用.     

实验性糖尿病大鼠血清一氧化氮与细胞因子的相关性研究

为观察实验性糖尿病大鼠血清一氧化氮与细胞因子的相关性 ,采用链脲佐菌素复制糖尿病动物模型 ,用比色法测定其血清一氧化氮 (nitric oxide,NO)含量和一氧化氮合成酶 (NO synthetase,NOS)活力 ,用放免法测定其血清中肿瘤坏死因子 (tumornecrosis factor,TNFα)和白细胞介素 -6 (Inter leukin-6 ,IL-6 )。结果显示 ,在实验性糖尿病大鼠血清中 NO与 TNFα和 IL -6均呈高度正相关 ,并且随病程延长 NO与 TNFα含量逐渐增加。     

板蓝根对脂多糖刺激鼠释放炎性细胞因子的影响

目的探讨板蓝根抗内毒素活性部位F022对脂多糖(LPS)刺激鼠单核细胞释放炎性细胞因子的影响。方法取BALB/C小鼠腹腔内单核细胞,实验设计为6组。其中,实验组根据F022浓度分为1%、0.5%、0.25%、0.125%4组,分别加入板蓝根F022部位液后再加入LPS液;LPS阳性组仅加入LPS液;阴性组加入1%F022液。之后检测细胞培养上清液中3种炎性细胞因子肿瘤坏死因子-α(TNF-α)、白细胞介素6(IL-6)和一氧化氮(NO)水平。结果LPS可刺激鼠单核细胞过度释放炎性细胞因子TNF-α、IL-6和NO;与阳性组比较,实验组炎性细胞因子水平降低,且呈剂量依赖性。结论板蓝根抗内毒素活性部位F022对LPS刺激鼠单核细胞过度释放炎性细胞因子具有抑制作用。     

慢性阻塞性肺病患者治疗前后细胞因子水平检测的临床意义

目的探讨IL-2、IL-1β、IL-10和TNF2在慢性阻塞性肺病(COPD)患者发病机制中的作用及意义。方法应用放射免疫法对40例COPD患者进行了血清IL-2、IL-1β、IL-10和TNF2水平测定,并与35名正常健康人作比较。结果 COPD患者在治疗前血清IL-2、IL-10水平显著低于正常人组(P<0.01),而IL-1β、TNF2水平又显著地高于正常人组(P<0.01),经治疗2周后与正常人的比较仍差异有显著性(P<0.05),血清IL-2水平与IL-10水平呈正相关(r值分别为0.4902,P值均小于0.01),与IL-1β、TNF2水平呈显著负相关(r值分别为-0.5184,-0.6028,P值均小于<0.01)。结论细胞因子参与COPD的气道炎症过程,观察细胞因子水平的变化可作为监测病情观测疗效和预后判定的重要指标之一。     

海洛因成瘾者血清中细胞因子含量变化与免疫功能损害

目的··:探讨海洛因成瘾者血清中细胞因子含量的变化及其与免疫功能损害的相互关系。方法··:用放射免疫法测定45例海洛因成瘾者和40例正常人血清中白细胞介素 -1(IL -1)、白细胞介素 -2(IL -2)和肿瘤坏死因子(TNF)的含量。结果··:海洛因成瘾者血清中3种细胞因子含量均显著低于正常组 (P<0.01)。结论··:海洛因成瘾者细胞因子含量降低很可能是造成成瘾者免疫功能 (特异性免疫和非特异性免疫 )损害的主要原因。     

动态检测细胞因子水平在病毒性心肌炎各期的临床价值

目的探讨细胞因子的动态水平在病毒性心肌炎各期的临床价值。方法采用放免法、化学比色法及酶联免疫法检测31例病毒性心肌炎患者和32例正常人的血清肿瘤坏死因子（TNF-a）、一氧化氮（NO）、白细胞介素-2,6（IL-2,IL-6）的动态水平。结果四种细胞因子的血清水平在病毒性心肌炎组均明显高于正常对照组,并呈急性期〉亚急性期〉恢复期。结论肿瘤坏死因子-a和一氧化氮、白介素均参与病毒性心肌炎的心肌细胞炎性损伤过程,其浓度变化可能具有双重作用。     

银杏内酯A和B及石杉碱甲抑制大鼠C6及人BT325胶质瘤细胞产生一氧 …

AIM: To study the effects of ginkgolide A, B (Gin A, Gin B) and huperzine A (Hup A) on nitric oxide (NO) production from cultured astrocytes. METHODS: Nitrites in supernatants were measured with Griess assay. RESULTS: Hup A 0.001-100 mumol.L-1 time- and concentration-dependently inhibited the NO production from rat C6 astrocytoma cells. The NO production from C6 cells was concentration-dependently inhibited by the treatment with Gin A or Gin B 0.001-10 micromol.L-1 for 24 h. The NO production from human BT325 astrocytoma cells was concentration-dependently inhibited by Hup A, Gin A, or Gin B 0.01-10 micromol.L-1 for 24 h. CONCLUSION: Gin A, Gin B, and Hup A inhibited astrocytes producing NO.     

Curcuminoid analogs inhibit nitric oxide production from LPS-activated microglial cells

The chemically modified analogs, the demethylated analogs 4–6, the tetrahydro analogs 7–9 and the hexahydro analogs 10–12, of curcumin (1), demethoxycurcumin (2) and bisdemethoxycurcumin (3) were evaluated for their inhibitory activity on lipopolysaccharide activated nitric oxide (NO) production in HAPI microglial cells. Di-O-demethylcurcumin (5) and O-demethyldemethoxycurcumin (6) are the two most potent compounds that inhibited NO production. The analogs 5 and 6 were twofold and almost twofold more active than the parent curcuminoids 1 and 2, respectively. Moreover, the mRNA expression level of inducible NO synthase was inhibited by these two compounds. The strong neuroprotective activity of analogs 5 and 6 provide potential alternative compounds to be developed as therapeutics for neurological disorders associated with activated microglia.     

Transmural pressure inhibits nitric oxide release from human endothelial cells.

We examined the effect of transmural pressure on histamine-stimulated nitric oxide release from cultured endothelial cells prepared from human umbilical cord veins. PO2 and pH were kept constant throughout the experiments. Various levels of transmural pressure and atmospheric pressure (40, 80, 120 and 160 mm Hg) were applied. Nitric oxide release was inhibited in a pressure-dependent manner. The inhibitory effects were reversible, and nitric oxide had no effect on the morphology of the cells. Our results suggest that transmural pressure-mediated inhibition of nitric oxide release contributes to pressure-induced vasoconstriction and reduced endothelium-dependent relaxation in patients with hypertension.     

Novel peptides enhance the production of nitric oxide and inducible nitric oxide synthase (iNOS) gene expression in murine macrophage

Bioactive novel polypeptide of anuran skin has a wide range of antimicrobial properties against the infection and tumour cell. Macrophages are known to produce the Nitric oxide (NO) by a variety of cells upon activation. NO produced by the activated macrophages an important mediator for antimicrobial and tumoricidal activity. In-vitro macrophage exposed with medium alone, containing LPS, containing polypepeptides and LPS plus polypeptides for 24 h showed enhanced production of NO with respect to control and LPS treated and significant increase in NO production in LPS plus polypeptide. Western blot and PCR analysis also showed that increased production of protein expression and mRNA expression of inducible nitric oxide synthase (iNOS). These findings suggest that novel polypeptides are potent activating agent for enhanced production of NO through activation of iNOS gene.     

Inhibitors of nitric oxide production from Stemona javanica

In our screening program for bioactive natural products from our library of tropical plants, the extract prepared from the roots of Stemona javanica inhibited NO production in mouse macrophage-like cell line J774.1 stimulated by lipopolysaccharide (LPS). Bioassay-guided fractionation of the extract from S. javanica led to the isolation of two active compounds, stemofoline (1) and stemanthrene C (2). The inhibition mechanism of 1 was proposed to suppress iNOS expression in J774.1 cells stimulated by LPS, whereas that of 2 was due to potent radical scavenging activity resulting in NO inhibitory activity.     

Thrombin-promoted release of UDP-glucose from human astrocytoma cells

As an increasing number of non-cardiac drugs have been reported to cause QT interval prolongation and torsades de pointes (TdP), we extensively studied the utility of atrioventricular (AV) block animals as a model to predict their torsadogenic action in human. The present review highlights such in vivo proarrhythmia models. In the case of the canine model, test substances were administered p.o. at conscious state >4 weeks after the induction of AV block, with subsequent Holter ECG monitoring to evaluate drug effects. Control AV block dogs (no pharmacological treatment) survive for several years without TdP attack. For pharmacologically treated dogs, drugs were identified as high, low or no risk. High-risk drugs induced TdP at 1-3 times the therapeutic dose. Low-risk drugs did not induce TdP at this dose range, but induced it at higher doses. No-risk drugs never induced TdP at any dose tested. Electrophysiological, anatomical histological and biochemical adaptations against persistent bradycardia-induced chronic heart failure were observed in AV block dogs. Recently, we have developed another highly sensitive proarrhythmia model using a chronic AV block cynomolgus monkey, which possesses essentially the same pathophysiological adaptations and drug responses as those demonstrated in the canine model. As a common remodelling process leading to a diminished repolarization reserve may present in patients who experience drug-induced TdP and in the AV block animals, the in vivo proarrhythmia models described in this review may be useful for predicting the risk of pharmacologically induced TdP in humans.     

Tea flavanols inhibit angiotensin-converting enzyme activity and increase nitric oxide production in human endothelial cells

A diversity of pharmacological effects on the cardiovascular system have been reported for Camellia sinensis: antioxidative, antiproliferative and anti-angiogenic activity, and nitric oxide synthase activation. The purpose of this study was to investigate if the connection between tea and angiotensin-converting enzyme (ACE) and nitric oxide (NO) might be an explanation of the pharmacological effects of tea on the cardiovascular system. Cultured endothelial cells from human umbilical veins (HUVEC) were incubated with extracts of Japanese Sencha (green tea), Indian Assam Broken Orange Pekoe (black tea) and Rooibos tea, respectively. The main flavanols and purine alkaloids in green and black tea were examined for their effects on ACE and NO. After incubation with green tea, black tea and Rooibos tea for 10 min, a significant and dose-dependent inhibition of ACE activity in HUVEC was seen with the green tea and the black tea. No significant effect on ACE was seen with the Rooibos tea. After 10-min incubation with (-)-epicatechin, (-)-epigallocatechin, (-)-epicatechingallate and (-)-epigallocatechingallate, a dose-dependent inhibition of ACE activity in HUVEC was seen for all four tea catechins. After 24-h incubation, a significantly increased dose-dependent effect on NO production in HUVEC was seen for the green tea, the black tea and the Rooibos tea. After 24-h incubation with (-)-epicatechin, (-)-epigallocatechin, (-)-epicatechingallate and (-)-epigallocatechingallate, a dose-dependent increased NO production in HUVEC was seen. In conclusion, tea extracts from C. sinensis may have the potential to prevent and protect against cardiovascular disease.     

Trichloroethylene induce nitric oxide production and nitric oxide synthase mRNA expression in cultured normal human epidermal keratinocytes

Trichloroethylene (TCE), a major chemical hazard during occupational exposure, can cause obvious skin lesions, including irritant reactions and dermatitis. Nitric oxide (NO) synthesized by nitric oxide synthase (NOS) is involved in a broad array of pathogenesis of skin inflammatory and immune responses. To understand the mechanisms of TCE-induced dermatoxicity, we investigated the effects of TCE on NO production and NOS mRNA expression in cultured normal human epidermal keratinocytes (NHEK). Cells were treated with TCE (0 mM, 0.125 mM, 0.25 mM, 0.5 mM, 1.0 mM, 2.0 mM) for 4 h, and then incubated for 12 h, 24 h, 48 h and 72 h. At each given time point, NO production were evaluated indirectly by measuring nitrite plus nitrate concentration in the culture medium using Griess reaction, as well as cell viability determined by MTT test, iNOS and cNOS activities assayed with a NOS activity detecting kit. The expression of iNOS and cNOS mRNA was detected using RT-PCR. TCE decreases cell viability and enhance NO production from NHEK in concentration- and time-dependent manner. Aminoguanidine (AG), an inhibitor of NOS, can prevent NO production and cell viability decrease in NHEK by TCE induced. Change to NO production was accompanied by increased activities of both types of NOS, but the iNOS activity accounted mainly for the TCE-induced NO production. RT-PCR detection showed that NHEK expressed both iNOS and cNOS mRNA by TCE exposure. Whereas a concentration- and time-dependent up-regulation of the mRNA expression was observed for iNOS and cNOS following TCE exposure, changes to iNOS were more marked. These results suggest that TCE caused increase in NO production, attributed to activation of iNOS as well as cNOS, and expression of iNOS and cNOS mRNA. These cellular changes may contribute to the pathological and physiological features of TCE-induced erythema and skin inflammation.