香菇多糖对巨噬细胞一氧化氮和一氧化氮合酶活性的影响

目的研究香菇多糖(LTN)诱导巨噬细胞的一氧化氮(NO)生成和一氧化氮合酶(iNOS)的活性,探讨LTN的免疫调节作用机理.方法采用Griess反应和荧光法测定不同剂量的LTN作用小鼠腹腔巨噬细胞后NO的生成量和iNOS活性.观察mRNA转录抑制剂、蛋白质合成抑制剂和iNOS抑制剂对巨噬细胞NO的生成和iNOS活性的影响.结果LTN能使小鼠腹腔巨噬细胞NO生成增加,iNOS活性增高,并呈作用剂量依赖关系.3种抑制剂均能抑制LTN诱导的小鼠腹腔巨噬细胞N0的生成和iNOS活性.结论LTN能刺激小鼠腹腔巨噬细胞提高iNOS活性和NO的生成.提示LTN的免疫调节作用机制可能与LTN刺激巨噬细胞NO生成有关.     

香菇多糖对巨噬细胞一氧化氦和一氧化氦合酶活性的影响

目的 研究香菇多糖(LTN)诱导巨噬细胞的一氧化氮(NO)生成和一氧化氮合酶(iNOS)的活性，探讨LTN的免疫调节作用机理。方法 采用Griess反应和荧光法测定不同剂量的LTN作用小鼠腹腔巨噬细胞后NO的生成量和iNOS活性。观察mRNA转录抑制剂、蛋白质合成抑制剂和iNOS抑制剂对巨噬细胞NO的生成和iNOS活性的影响。结果 LTN能使小鼠腹腔巨噬细胞NO生成增加，iNOS活性增高，并呈作用剂量依赖关系。3种抑制剂均能抑制LTN诱导的小鼠腹腔巨噬细胞NO的生成和iNOS活性。结论 LTN能刺激小鼠腹腔巨噬细胞提高iNOS活性和NO的生成。提示LTN的免疫调节作用机制可能与LTN刺激巨噬细胞NO生成有关。     

花色素苷诱导小鼠巨噬细胞一氧化氮生成及其机制

目的研究花色素苷对小鼠腹腔巨噬细胞一氧化氮(NO)合成的诱导作用及其机制。方法用CCK-8试剂检测花色素苷对小鼠脾细胞增殖的影响;硝酸盐还原酶法检测小鼠腹腔巨噬细胞NO含量;荧光法检测一氧化氮合酶(NOS)活性;RT-PCR检测iNOS mRNA的表达。结果花色素苷可促进小鼠脾细胞增殖,诱导小鼠腹腔巨噬细胞合成NO,提高NOS活性,其中矢车菊素-3-葡萄糖苷能够诱导iNOS mRNA的表达。结论花色素苷能够促进脾细胞的增殖,诱导小鼠腹腔巨噬细胞合成NO,使巨噬细胞激活,具有一定的免疫调节活性。     

细脚拟青霉多糖诱导小鼠巨噬细胞一氧化氮生成和iNOS mRNA的表达

目的研究单一组分细脚拟青霉多糖(Paecilomyces tenuipespolysaccharide,PTPS)诱导小鼠腹腔巨噬细胞的免疫调节活性及其作用机制。方法应用水提、乙醇沉淀、DEAE-纤维素色谱,对PTPS进行提取并分级;用CCK-8试剂检测PTPS对小鼠脾细胞的增殖作用,硝酸盐还原酶法检测小鼠腹腔巨噬细胞一氧化氮(NO)的生成量和RT-PCR半定量法检测iNOS mRNA的表达。结果从细脚拟青霉菌丝体中分离出含糖量为92%的中性多糖PTPS,可促进脾细胞的增殖,并在一定浓度下显示剂量依赖效应;能明显诱导小鼠腹腔巨噬细胞NO的生成和iNOS mRNA的表达。结论PTPS通过诱导小鼠巨噬细胞NO合成和iNOS的转录,表明其具有免疫调节和潜在的抗肿瘤活性。     

灵芝多糖肽对小鼠腹腔巨噬细胞一氧化氮产生的影响

目的　研究灵芝多糖肽 (GLPP)对小鼠腹腔巨噬细胞一氧化氮产生的影响并探讨其作用机制。方法　以Griess法 ,观察GLPP对LPS诱导小鼠腹腔巨噬细胞一氧化氮(NO)产生的影响 ;以免疫组化法检测诱导型一氧化氮合成酶 (iNOS)的表达 ,观察GLPP对iNOS的影响。结果　GLPP(2 5～ 2 0 0mg·kg-1)灌胃给药 5d或体外给药 (3 12 5～ 2 0 0mg·L-1)均可促进巨噬细胞NO释放 ,但对LPS刺激NO的释放影响不大 ;GLPP(10 0mg·kg-1)灌胃给药 5d或体外给药 (10mg·L-1)均可使巨噬细胞iNOS含量增加。结论　GLPP可增加小鼠腹腔巨噬细胞NO产生 ,其机制可能与其促进巨噬细胞iNOS合成有关。     

库拉索芦荟多糖对小鼠腹腔巨噬细胞一氧化氮生成的影响

目的研究库拉索芦荟多糖对小鼠腹腔巨噬细胞一氧化氮(NO)生成的影响。方法用G riess法测定巨噬细胞一氧化氮的生成量。结果库拉索芦荟多糖在25～400μg/mL浓度范围可显著促进正常巨噬细胞的NO生成,在50～400μg/mL浓度范围可抑制LPS激活的巨噬细胞的NO生成。结论库拉索芦荟多糖对小鼠腹腔巨噬细胞一氧化氮的生成具有双向调节作用。     

库拉索芦荟多糖对小鼠腹腔巨噬细胞一氧化氮生成的影响

目的研究库拉索芦荟多糖对小鼠腹腔巨噬细胞一氧化氮(NO)生成的影响。方法用G riess法测定巨噬细胞一氧化氮的生成量。结果库拉索芦荟多糖在25~400μg/mL浓度范围可显著促进正常巨噬细胞的NO生成,在50~400μg/mL浓度范围可抑制LPS激活的巨噬细胞的NO生成。结论库拉索芦荟多糖对小鼠腹腔巨噬细胞一氧化氮的生成具有双向调节作用。     

酵母多糖对小鼠腹腔巨噬细胞产生一氧化氮和白细胞介素-1的影响

目的探讨酵母多糖对小鼠腹腔巨噬细胞产生一氧化氮 (NO)和白细胞介素 1(IL 1)的影响。方法将不同剂量的酵母多糖加入体外培养的小鼠腹腔巨噬细胞中 ,取细胞培养上清液根据Griess反应检测NO-2 的量 ,间接反映巨噬细胞产生NO的生成量 ,并用溴化四唑蓝 (MTT)比色法检测上清液中IL 1的生成量。结果酵母多糖可明显促进小鼠腹腔巨细胞产生NO和IL 1,NO的生成量呈现剂量依赖关系。结论酵母多糖可诱导小鼠腹腔巨噬细胞产生NO和IL 1,可能是酵母多糖调节机体免疫功能、杀伤病原微生物和抗肿瘤的重要途径     

12味止血中药对脂多糖诱导小鼠巨噬细胞产生一氧化氮的抑制作用

目的:研究12味止血中药对脂多糖(LPS)诱导小鼠巨噬细胞产生一氧化氮(NO)的抑制作用,并探讨其止血机制。方法:以1μg.mL-1LPS刺激小鼠巨噬细胞RAW264.7,22h后以Griess法测定NO的终产物亚硝酸盐的含量,观察LPS对NO生成的影响。结果:12味止血药均可抑制LPS诱导小鼠巨噬细胞RAW264.7中NO的生成。三七、地榆、仙鹤草、槐花、艾叶、蒲黄、侧柏叶及白茅根的抑制作用显著(P<0.05)。结论:本实验为12味止血中药对脂多糖诱导小鼠巨噬细胞产生NO的抑制作用提供了一定的理论依据。     

木酚素二硫戊环类似物抑制γ-干扰素和脂多糖在巨噬细胞中诱生一氧化氮(英文)

目的:研究木酚素二硫戊环类似物及血小板活化因子(PAF)受体拮抗剂L-659,989对PAF-受体结合,对γ-干扰素和脂多糖诱导的一氧化氮(NO)生成,以及对iNOS mRNA表达的影响.方法:通过对兔血小板膜中~3H标记的PAF-受体竞争结合试验来研究对PAF-受体的拮抗作用;测定NO的氧化产物亚硝酸盐来定量NO的生成.用RNA印迹分析来研究对iNOS mRNA表达的影响.结果:二硫戊环类似物抑制NO的生成,减少iNOS mRNA的表达,拮抗~3HPAF受体.L-659,989对NO生成和iNOS mRNA表达没有影响.受试物的PAF受体拮抗活性和iNOS抑制活性之间无简单关联.结论:木酚素二硫戊环类似物是iNOS表达的新型调控剂,具有抑制iNOS,诱导和拮抗PAF受体的双重活性.     

Substance P augments nitric oxide production and gene expression in murine macrophages.

We investigated the effects of substance P (SP) on nitric oxide (NO) synthase activity in macrophages by measuring the production of nitrite and the expression of inducible NO synthase (iNOS) mRNA and protein. In LPS-activated macrophages, SP stimulated NO production in time and concentration dependent manners. These SP effects were blocked by a specific NK-1 receptor antagonist. Furthermore, SP stimulation increased the levels of both iNOS mRNA and iNOS protein. These results demonstrate that SP can increase LPS induced NO production in macrophages by augmenting the induction of iNOS expression. We also examined the role of SP on acute-cold stress induced altered production of NO by mouse peritoneal macrophages. SP enhanced the LPS-induced macrophages NO production from stressed mice relative to the non-stressed mice. These results suggest that SP may have an important modulatory role in production of NO by macrophages.     

Equol inhibits nitric oxide production and inducible nitric oxide synthase gene expression through down-regulating the activation of Akt

In the present study, we report the inhibitory effect of equol on nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) gene expression in murine macrophages. In vivo administration of equol (i.p.) attenuated NO production by peritoneal adherent cells isolated from lipopolysaccharide (LPS)-treated mice. Equol dose-dependently inhibited the LPS-induced production of NO in isolated peritoneal adherent cells and RAW 264.7 cells. The mRNA expression of iNOS was also blocked by equol in LPS-stimulated RAW 264.7 cells. Further study demonstrated that the LPS-induced activation of Akt was suppressed by equol in RAW 264.7 cells while the activation of ERK, SAPK/JNK and p38 MAP kinase was not affected. Equol also blocked LPS-induced NF-kappaB activation. Moreover, the LPS-induced NO production and NF-kappaB activation was inhibited by LY294002, a specific inhibitor of phosphatidylinositol 3-kinase/Akt pathway, in RAW 264.7 cells. These results suggest that equol might inhibit NO production and iNOS gene expression, at least in part, by blocking Akt activation and subsequent down-regulation of NF-kappaB activity.     

Putative role of nitric oxide synthase isoforms in the changes of nitric oxide concentration in rat brain cortex and cerebellum following sevoflurane and isoflurane anaesthesia

We have previously observed an increase in nitric oxide (NO) content in rat brain cortex following halothane, sevoflurane or isoflurane anaesthesia. This study was undertaken in order to determine whether isoform-specific nitric oxide synthase (NOS) inhibitors and inducers could modify these increases in NO contents. Rats were subjected to isoflurane and sevoflurane anaesthesia with concomitant administration of neuronal nitric oxide synthase (nNOS) inhibitor 7-Nitro-indazole (7-NI), inducible nitric oxide synthase (iNOS) inhibitor 2-amino-5,6-dihydro-6-methyl-4H-1,3-thiazine (AMT) or lipopolysaccharide. NO concentration in different organs was measured by electron paramagnetic resonance (EPR) spectroscopy. 7-NI significantly decreased NO concentration in cerebellum but not in brain cortex, whereas AMT decreased NO in all the organs studied. Anaesthesia significantly increased NO concentration in brain cortex and decreased that in cerebellum. AMT abolished the NO increase in brain cortex. Anaesthesia enhanced the drastic increase in NO concentration in brain cortex after intraventricular lipopolysaccharide administration. Isoflurane was found to inhibit recombinant nNOS and iNOS activities at high concentrations (EC50=20 mM). Our data suggest a putative role for iNOS in the increase in NO levels produced by isoflurane and sevoflurane, whereas nNOS activity is probably inhibited during anaesthesia.     

细胞因子对膀胱平滑肌细胞内诱导性一氧化氮合酶的激活作用(英文)

探讨肿瘤坏死因子α (TNFα)和γ干扰素(INFγ)对大鼠膀胱平滑肌细胞诱导性一氧化氮合酶(iNOS )的影响 .将TNFα (1nmol·L- 1)或INFγ(5 0kU·L- 1)分别或同时加入膀胱平滑肌细胞培养液 ,2 4h后测定细胞培养液中一氧化氮 (NO)水平 ,并用Western印迹方法检测iNOS的表达 .结果显示 ,TNFα或INFγ单独不能诱导iNOS表达 ,也不能引起NO水平显著提高 .但当TNFα和INFγ联合诱导细胞 2 4h ,则细胞培养液中NO水平明显升高 ,用Western印迹分析可见iNOS表达 ,说明TNFα和INFγ具有协同诱导作用 .在TNFα和INFγ加入膀胱平滑肌细胞前 30min ,加入NOS抑制剂L 氮 精氨酸甲酯 (L NAME) ,可显著抑制TNFα和INFγ对NO的生成诱导 .结果提示 ,TNFα和INFγ联合应用可激活膀胱平滑肌细胞iNOS .     

YC-1 potentiates cAMP-induced CREB activation and nitric oxide production in alveolar macrophages

Alveolar macrophages play significant roles in the pathogenesis of several inflammatory lung diseases. Increases in exhaled nitric oxide (NO) are well documented to reflect disease severity in the airway. In this study, we investigated the effect of 3-(5′-hydroxymethyl-2′-furyl)-1-benzyl indazole (YC-1), a known activator of soluble guanylyl cyclase, on prostaglandin (PG)E₁ (a stable PGE₂ analogue) and forskolin (a adenylate cyclase activator) induced NO production and inducible NO synthase (iNOS) expression in rat alveolar macrophages (NR8383). YC-1 did not directly cause NO production or iNOS expression, but drastically potentiated PGE₁- or forskolin-induced NO production and iNOS expression in NR8383 alveolar macrophages. Combination treatment with YC-1 and PGE₁ significantly increased phosphorylation of the cAMP response element-binding protein (CREB), but not nuclear factor (NF)-κB activation. The combined effect on NO production, iNOS expression, and CREB phosphorylation was reversed by a protein kinase (PK)A inhibitor (H89), suggesting that the potentiating functions were mediated through a cAMP/PKA signaling pathway. Consistent with this, cAMP analogues, but not the cGMP analogue, caused NO release, iNOS expression, and CREB activation. YC-1 treatment induced an increase in PGE₁-induced cAMP formation, which occurred through the inhibition of cAMP-specific phosphodiesterase (PDE) activity. Furthermore, the combination of rolipram (an inhibitor of PDE4), but not milronone (an inhibitor of PDE3), and PGE₁ also triggered NO production and iNOS expression. In summary, YC-1 potentiates PGE₁-induced NO production and iNOS expression in alveolar macrophages through inhibition of cAMP PDE activity and activation of the cAMP/PKA/CREB signaling pathway.     

褪黑素抑制一氧化氮生成在小鼠免疫性肝损伤中的意义

目的探讨褪黑素（ＭＴ）抑制一氧化氮生成与保护免疫性肝损伤的关系。方法用短小棒状杆菌和脂多糖诱导小鼠免疫性肝损伤模型；分离、培养肝细胞和腹腔巨噬细胞；检测一氧化氮（ＮＯ）、丙氨酸氨基转换酶（ＡＬＴ）、丙二醛（ＭＤＡ）和谷胱甘肽过氧化酶（ＧＳＨ ｐｘ）变化。结果ＭＴ在０１～１０ｍｇ·ｋｇ－１·ｄ－１浓度范围内，明显降低小鼠免疫性肝损伤中ＭＬＴ和ＭＤＡ水平，部分恢复ＧＳＨ ｐｘ活性（Ｐ＜００５～００１），同时血浆ＮＯ水平下降（Ｐ＜００５）。左旋单甲基精氨酸则在显著降低血浆ＮＯ水平（Ｐ＜００１）同时，肝损伤征象加重。体外用ＭＴ对肝细胞和巨噬细胞无明显影响。结论褪黑素抑制体内ＮＯ过度生成，有利于保护免疫性肝损伤。     

In vitro induction of nitric oxide by mouse peritoneal macrophages treated with human placental extract

Nitric oxide (NO) is an important cellular mediator of tissue repair. It is produced in macrophages by the enzyme inducible nitric oxide synthase (iNOS) during wound healing. An aqueous extract of human placenta used as wound healer, has been investigated in terms of induction of NO by mouse peritoneal macrophages as well as human monocyte derived macrophages. NO production was estimated in macrophages culture supernatants. Incubation of 0.1 to 20 mg/ml of placental extract with 2x10(6) cells in vitro produced 10 to 100 microM of nitrite (n=4) in a dose dependent manner suggesting production of NO. With increase of NO production, NADPH present in the applied extract decreased proportionately. Application of L-NG monomethyl arginine (L-NMMA), an NO synthase (NOS) inhibitor, reduced the production of NO at the basal level. Dose dependent release of IFN-gamma with respect to placental extract by the mouse macrophages was observed. It has been observed that human monocytes derived macrophages also produced significant amount of NO by induction of the extract. Similar induction of NO by placental extract in presence and absence of polymyxin B suggested that this property is not likely to be mediated by the endotoxin/LPS.