选择性抑制一氧化氮合酶对大鼠小体积肝移植的影响

目的:探讨诱导性一氧化氮合成酶(iNOS)在大鼠小体积肝移植模型中的作用?方法:选取清洁雄性Spraque-Dawley大鼠90只?采用改良的二袖套法建立吻合肝动脉的小移植物模型?实验分为3组:正常对照组?小体积肝移植组和氨基胍(AG)注射组?术后分别在1?3? 6?12 h等4个时间点处死5只大鼠并采取部分肝组织及血清样本?检测指标:血清丙氨酸转氨酶(ALT),实时荧光定量RT-PCR 测定肝组织iNOS mRNA 的表达,免疫组化法测定肝组织iNOS 蛋白的表达,HE染色光镜下病理观察等?结果:AG组与小体积肝移植组相比,实时荧光定量PCR显示:肝组织中iNOS mRNA 表达量明显下降(P < 0.05,n = 5);免疫组化显示:肝组织中iNOS 蛋白表达下降;但ALT 明显升高(P < 0.05,n = 5);病理显示肝细胞大量坏死?结论:AG 能抑制iNOS 在大鼠小体积模型中的表达,但不能减轻肝脏损伤,反而加重了损伤?     

iNOS在复发性翼状胬肉中的表达及意义

目的：检测诱导型一氧化氮合酶（iNOS）在复发性翼状胬肉组织中的表达水平,初步探讨iNOS在翼状胬肉复发过程的作用机制.方法：应用SP免疫组织化学染色法检测5例正常结膜组织、6例原发性翼状胬肉组织及22例复发性翼状胬肉组织中iNOS的免疫学定位及表达,分析iNOS在正常结膜、原发性翼状胬肉及复发性翼状胬肉中的表达差异.结果：iNOS在正常结膜组织、原发性翼状胬肉组织及复发性翼状胬肉组织的表达组间差异有统计学意义,P＜0.05.结论：iNOS在复发性翼状胬肉中呈高表达,提示iNOS能促进新生血管形成,可能与翼状胬肉术后复发有关.     

Ginseng aqueous extract ameliorates lambda‐cyhalothrin‐acetamiprid insecticide mixture for hepatorenal toxicity in rats: Role of oxidative stress‐mediated proinflammatory and proapoptotic protein expressions

This study was carried out to evaluate the protective effects of Panax ginseng aqueous extract (GAE) against hepatorenal toxicity induced by lambda‐cyhalothrin‐acetamiprid insecticide mixture in rats. A total of 32 male albino rats were assigned into four groups. Normal control group received distilled water. Insecticide control group intoxicated with the insecticide at a dose of 2.14 mg/kg b.wt orally day after day for 45 days. GAE control group was treated with GAE at a dose 200 mg/kg b.wt orally. GAE experimental group was administered GAE 1 hour before insecticide administration. Intoxication of rats with the insecticide caused a significant increase in serum aspartate aminotransferase and alanine aminotransferase activities and urea and creatinine levels as well as malondialdehyde concentration and proteins expression of caspase‐3 and induced nitric oxide synthase in hepatic and renal tissues. However, it decreased the serum levels of total protein and globulin and reduced the glutathione content and catalase activity in hepatic and renal tissues. In addition, insecticide induced histopathological alterations in both hepatic and renal tissues. In contrast, GAE modulated insecticide‐induced alterations in liver and kidney functions and structures as it ameliorated the effects of insecticide on the above mentioned parameters. These results indicated that GAE was a potent antioxidant agent that could protect rats against insecticide‐induced hepatorenal toxicity.     

Anti-inflammatory effects of peptides from a marine algicolous fungus Acremonium sp. NTU492 in BV-2 microglial cells

Located in tropical and subtropical region, Taiwan is an island with high algal species diversity. In this study, a number of fungal strains were isolated from marine macroalgae collected from northeastern intertidal zone of Taiwan. Preliminary anti-inflammatory screening has shown that the methanolic extracts of solid fermented products of the red alga Mastophora rosea-derived fungal strain Acremonium sp. NTU492 exhibited significant bioactivity. In an attempt to disclose the active principles from this fungal strain, a series of separation and purification was thus undertaken, which has led to the isolation and characterization of seven compounds including four new peptides, namely acrepeptins A–D (1–4), along with previously reported destruxin B (5), guangomide A (6), and guangomide B (7). Their structures were elucidated by spectroscopic analysis and compared with literatures. Of these, acrepeptins A (1) and C (3) showed markedly inhibitory activities on nitric oxide production in lipopolysaccharide-activated microglial BV-2 cells with IC₅₀ values of 12.0 ± 2.3 and 10.6 ± 4.0 μM, respectively. Furthermore, acrepeptins A (1) and C (3) significantly attenuated the expression of inducible nitric oxide synthase in a concentration-dependent manner (5–40 μM).     

粉防己碱对脂多糖诱导下RAW264.7细胞COX-2/PGE2、iNOS/NO表达的影响

本实验旨在观察粉防己碱（Tet）对脂多糖（LPS）诱导下RAW264.7细胞炎症模型的抗炎作用。采用 LPS 1 μg/mL刺激生长良好的RAW264.7巨噬细胞建立细胞炎症模型。在不同浓度Tet（1×10^-8,1×10^-7,1×10^-6mol/L）作用下,用Western blotting检测各组细胞中环加氧酶-2（COX-2）和诱导性一氧化氮激酶（iNOS）的表达,用NO检测试剂盒检测细胞培养液中NO的含量,酶免疫分析法检测培养液中前列腺素E₂（PGE₂）含量。结果显示Tet剂量依赖性地抑制LPS诱导的RAW264.7细胞PGE₂、NO的表达,同时抑制其合成酶COX-2和iNOS的表达。表明Tet具有抑制LPS诱导的RAW264.7细胞炎症反应的作用,其抗炎机制可能通过抑制COX-2、iNOS的表达,从而抑制其下游炎性介质NO、PGE₂的表达有关。     

颈交感神经干离断对局灶性脑缺血再灌注后大鼠海马iNOS表达的影响

目的采用颈交感干离断（TCST）模拟星状神经节阻滞，观察其对局灶性脑缺血再灌注损伤（CIRI）大鼠脑梗死容积及海马诱导型一氧化氮合酶（iNOS）表达等的影响，并探讨其脑保护作用的机制。方法将大鼠随机分成实验组（A组）、对照组（B组）和假手术组（C组）；采用线栓法行大脑中动脉栓塞（MCAO）制作大鼠局灶性CIRI模型，A组于TCST后即行MCAO，2h后再恢复灌注；B组为单纯CIRI组；C组仅完成与A组相似的手术步骤但不造成MCAO、不行TCST；再灌注24h后观察各组大鼠神经行为学评分、脑梗死容积及海马iNOs的表达变化。结果A组大鼠脑梗死容积和神经行为学评分均低于B组（P〈0．05）；与A组、C组相比，B组大鼠海马iNOS的表达增加（P〈0．05），而A组与C组间无显著差异（P〉0．05）。结论TCST可通过下调大鼠海马iNOS的表达而对局灶性CIRI发挥脑保护作用。     

Catalpol protects primary cultured astrocytes from in vitro ischemia-induced damage

Catalpol, an iridoid glycoside abundant in the roots of Rehmannia glutinosa, has been previously found to prevent the loss of CA1 hippocampal neurons and to reduce working errors in gerbils after ischemia-reperfusion injury. In the present study, we investigated the effects of catalpol on astrocytes in an ischemic model to further characterize its neuroprotective mechanisms. Primary cultured astrocytes exposed to oxygen-glucose deprivation (OGD) followed by reperfusion (adding back oxygen and glucose, OGD-R), were used as an in vitro ischemic model. Treatment of the astrocytes with catalpol during ischemia-reperfusion increased astrocyte survival significantly in a concentration-dependent manner, as demonstrated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, lactate dehydrogenase (LDH) release and morphological observation. In addition, catalpol prevented the decrease in mitochondrial membrane potential, inhibited the formation of reactive oxygen species (ROS) and the production of nitric oxide (NO), decreased the level of lipid peroxide and the activity of inducible nitric oxide synthase (iNOS), and elevated the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and the content of glutathione (GSH). Our results suggest that catalpol exerts the most significant cytoprotective effect on astrocytes by suppressing the production of free radicals and elevating antioxidant capacity.     

An animal model of chronic inflammatory pain: pharmacological and temporal differentiation from acute models.

Clinically, inflammatory pain is far more persistent than that typically modelled pre-clinically, with the majority of animal models focussing on short-term effects of the inflammatory pain response. The large attrition rate of compounds in the clinic which show pre-clinical efficacy suggests the need for novel models of, or approaches to, chronic inflammatory pain if novel mechanisms are to make it to the market. A model in which a more chronic inflammatory hypersensitivity phenotype is profiled may allow for a more clinically predictive tool. The aims of these studies were to characterise and validate a chronic model of inflammatory pain. We have shown that injection of a large volume of adjuvant to the intra-articular space of the rat knee results in a prolonged inflammatory pain response, compared to the response in an acute adjuvant model. Additionally, this model also results in a hypersensitive state in the presence and absence of inflammation. A range of clinically effective analgesics demonstrate activity in this chronic model, including morphine (3mg/kg, t.i.d.), dexamethasone (1mg/kg, b.i.d.), ibuprofen (30mg/kg, t.i.d.), etoricoxib (5mg/kg, b.i.d.) and rofecoxib (0.3-10mg/kg, b.i.d.). A further aim was to exemplify the utility of this chronic model over the more acute intra-plantar adjuvant model using two novel therapeutic approaches; NR2B selective NMDA receptor antagonism and iNOS inhibition. Our data shows that different effects were observed with these therapies when comparing the acute model with the model of chronic inflammatory joint pain. These data suggest that the chronic model may be more relevant to identifying mechanisms for the treatment of chronic inflammatory pain states in the clinic.     

氟骨症患者血清一氧化氮含量和外周血白细胞诱导型一氧化氮合酶mRNA表达的意义

目的　探讨氟骨症患者患者外周血白细胞诱导型一氧化氮合酶(induciblenitricoxidesynthaseiNOS)mRNA表达的意义。方法　选择3 5例氟骨症患者患者及3 0例正常人的外周血白细胞。iNOS -mRNA表达采用原位杂交方法。血浆一氧化氮(nitricoxideNO)水平采用硝酸还原酶比色法测定。结果　正常人外周血白细胞未见iNOS -mRNA表达,而氟骨症患者外周血白细胞iNOS -mRNA表达高度增强,其阳性率达40 .82 %。AR组血清NO水平显著高于对照组(t =2 7.89,P <0 .0 1)。结论　氟骨症患者病人血清NO水平与外周血白细胞iNOS -mRNA表达高度增强有关。提示iNOS-NO通路在氟骨症的发病过程中可能起重要作用。本研究为检测体内某些信号提供了简便易行的原位杂交试验方法。     

Selective inducible nitric oxide synthase inhibition attenuates organ dysfunction and elevated endothelin levels in LPS-induced DIC model rats

Summary. We examined the role of nitric oxide (NO) produced by an inducible isoform of NO synthase (iNOS) using N[6]‐(iminoethyl)‐lysine (L‐NIL), a selective iNOS inhibitor, in the rat model of lipopolysaccharide (LPS)‐induced disseminated intravascular coagulation (DIC) and investigated changes in organ function, plasma levels of NOX (metabolites of NO) and endothelin. We induced experimental DIC by the sustained infusion of 30 mg kg^?1 LPS for 4 h via the tail vein. We then investigated the effect of L‐NIL (6 mg kg^?1, from ? 0.5 to 4 h) on LPS‐induced DIC. Blood was withdrawn at 4 and 8 h, and all four groups (LPS with or without L‐NIL at 4 and 8 h) consisted of eight rats. Three of the animals in the 8‐h LPS group died, and we examined blood samples from five rats in this group. None of the other rats died. The LPS‐induced elevation of creatinine, alanine aminotransferase, glomerular fibrin deposition and plasminogen activator inhibitor was significantly suppressed by L‐NIL coadministration, although L‐NIL did not affect the platelet count, fibrinogen concentration or the level of thrombin–antithrombin complex. Moreover, plasma levels of the D‐dimer that reflect the lysis of cross‐linked fibrin were significantly increased by L‐NIL coadministration in the LPS‐induced DIC model. Plasma levels of NOX and endothelin were obviously increased by LPS infusion. However, both levels were significantly suppressed in the LPS + L‐NIL group, when compared with the LPS group. Although mean arterial pressure (MAP) was significantly decreased between 2 and 8 h compared with the control in the LPS group, this depression was significantly attenuated in the LPS + L‐NIL group. Our results suggest that NO induced by iNOS contributes to hypotension (depressed MAP), the progression of hepatic and renal dysfunction, microthrombus deposition and elevated endothelin levels in the rat model of LPS‐induced DIC.