血脂康对急性冠脉综合征患者内皮功能的影响

目的观察血脂康对急性冠脉综合征患者血清一氧化氮（NO）及一氧化氮合酶（NOS）的影响。方法随机选择急性冠脉综合征病患者67例．将其随机分为血脂康治疗组35例，阿托伐他汀组32例，并对两组患者治疗前后血清NO及NOS含量水平进行对比分析。结果血脂康和阿托伐他汀均可升高急性冠脉综合征患者血清NO及NOS水平，其作用无明显差异（P〉0．05）。结论血脂康可抑制脂质过氧化反应．保护血管内皮功能，对急性冠脉综合征的防治具有重要意义。     

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.     

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。     

12味止血中药对脂多糖诱导小鼠巨噬细胞产生一氧化碳的抑制作用

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-1 LPS刺激小鼠巨噬细胞RAW 264.7,22h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RAW 264.7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.     

一氧化氮合成酶抑制剂的研究进展

一氧化氮（NO）具有广泛的生理功能。哺乳动物体内的NO是由NO合成酶（NOS）氧化L－精氨酸而合成的,合成后的NO迅速跨膜扩散释放。NO合成失调能介导多种疾病产生。特异性NO抑制剂能通过调控NO的合成,对NOS表达相关的各种疾病的防治具有重要的临床意义。本文对近年来NOS抑制剂的研究作一概述。     

Inhibitory Effects of Baicalein and Wogonin on Lipopolysaccharide-Induced Nitric Oxide Production in Macrophages

Abstract: In order to elucidate the mechanism of the antiinflammatory action of baicalein and wogonin, flavonoids from the root of Scutellaria baicalensis, the effects of these compounds were investigated on lipopolysaccharide-induced nitric oxide production in a macrophage-derived cell line, RAW 264.7. Baicalein (5–25 μM) and wogonin (5–50 μM) inhibited lipopolysaccharide-induced nitric oxide generation in a concentration-dependent manner. The inhibitory effect of these compounds was observed only when they were added at the start of cell incubation soon after the stimulation with lipopolysaccharide. Baicalein (25 μM) and wogonin (25 μM) also inhibited protein expression of inducible nitric oxide synthase. This inhibitory effect of wogonin was stronger than that of baicalein, which agrees with the result that wogonin showed stronger inhibition of nitric oxide production than baicalein. These results suggest that baicalein and wogonin attenuate lipopolysaccharide-stimulated nitric oxide synthase induction in macrophages and thus may help to explain the antiinflammatory action of these flavonoid compounds.     

Nitric Oxide Modulators: An Emerging Class of Medicinal Agents

Nitric oxide, a unique messenger in biological system, is ubiquitously present virtually in all tissues revealing its versatile nature of being involved in diverse physiological functions such as vascular tone, inhibition of platelet aggregation, cell adhesion, neurotransmission and enzyme and immune regulation. The tremendous advancements made in the past few decades in this area suggests that the nitric oxide modulation either by its exogenous release through nitric oxide donors or inhibition of its synthesis by nitric oxide synthase inhibitors in physiological milieu may provide newer clinical strategies for the treatment of some diseases. In this review, an attempt is made to document and understand the biological chemistry of different classes of nitric oxide modulators that would prove to be a fruitful area in the years to come.     

Shikonin Directly Inhibits Nitric Oxide Synthases: Possible Targets That Affect Thoracic Aorta Relaxation Response and Nitric Oxide Release From RAW 264.7 Macrophages

Recently, an isomeric mixture of herbal anti-inflammatory naphthoquinones shikonin and alkannin, and their derivatives, have been found to impair cellular responses involving nitric oxide (NO) and NO synthesis, like the acetylcholine-induced relaxation response of rat thoracic aorta and NO release from murine RAW 264.7 macrophages. However, the mechanisms of such effects, including whether NO synthase (NOS) activity is affected, remained unclear. We herein investigate possible targets of shikonin in these NOS-related events. Shikonin by itself dose-dependently inhibited the rat thoracic aorta relaxation in response to acetylcholine (pD′₂ value: 6.29). Its optical enantiomer, alkannin, was equally inhibitory in the aorta relaxation–response assay. In RAW 264.7 cells, shikonin inhibited the lipopolysaccharide-induced NO production by 82% at 1 μM. A cell-free assay to verify direct effects on NOS activity showed that shikonin inhibits all isoforms of NOS (IC₅₀ s, 4–7 μM), suggesting NOS as an inhibition target in both the events. Further possible targets of shikonin that might be involved in the inhibitions of the acetylcholine-induced aorta relaxation response and the NO generation by RAW 264.7 cells are also discussed. It is shown for the first time that shikonin inhibits NOS activity.     

二苯乙烯苷预防性干预大鼠动脉硬化对其一氧化氮合酶表达的影响

目的探讨二苯乙烯苷(TSG)对动脉粥样硬化(AS)大鼠一氧化氮(NO)含量及主动脉一氧化氮合酶(NOS)表达的影响。方法SD大鼠60只,♂,随机分为6组:①正常对照组;②模型组;③TSG低剂量组;④TSG中剂量组;⑤TSG高剂量组;⑥辛伐他汀阳性对照组。造模12wk后,颈动脉取血,检测血清NO含量。取血后分离主动脉,保存于-70℃,检测主动脉组织中NOS含量,RT-PCR检测大鼠主动脉eNOS和iNOS mRNA表达。实验数据采用STATA8.0软件进行统计分析。结果与模型组相比,辛伐他汀组和TSG各剂量组均能增加血清及主动脉组织NO的含量、主动脉组织NOS的水平、主动脉组织eNOS mRNA的表达及降低主动脉组织iNOS mRNA的表达,并呈剂量依赖性。结论TSG能上调AS大鼠动脉壁eNOS mRNA的表达,抑制AS大鼠动脉壁iNOS mRNA的表达,这可能是TSG抗AS的机制之一。     

一氧化氮合酶抑制剂的研究进展

一氧化氮（NO）具有广泛的生理功能,哺乳动物体内的NO是由NO合酶（NOS）氧化L－精氨酸而合成的,合成后的NO迅速跨膜扩散释放,NO合成失调能介导多种疾病产生,特异性NOS抑制剂能通过调控NO的合成,对NOS表达相关的各种疾病的防治具有重要的临床意义,本文对近年来NOS抑制剂的研究作一概述。     

Andrographolide suppresses the expression of inducible nitric oxide synthase in macrophage and restores the vasoconstriction in rat aorta treated with lipopolysaccharide

1. We investigated whether andrographolide, a diterpenoid lactone found at Andrographis paniculata, influences the induction of the inducible nitric oxide synthase (iNOS) in RAW264.7 cells activated by bacterial endotoxin (LPS), as well as in the rats with endotoxic shock and in aortic rings treated with LPS.
2. Incubation of RAW264.7 cells with andrographolide (1 to 50 μM) inhibited the LPS (1 μg ml⁻¹)-induced nitrite accumulation in concentration- and time-dependent manners. Maximum inhibition was observed when andrographolide was added together with LPS and decreased progressively as the interval between andrographolide and LPS was increased to 20 h.
3. Western blot analysis demonstrated that iNOS expression was markedly attenuated in the presence of andrographolide for 6–24 h, suggesting that andrographolide inhibited iNOS protein induction.
4. Thoracic aorta incubation with LPS (300 ng ml⁻¹) for 5 h in vitro exhibited a significant decrease in the maximal contractile response to phenylephrine (10⁻⁹–10⁻⁵ M). Andrographolide (30 μM) restored the contractile response to control level.
5. In anaesthetized rats, LPS (10 mg kg⁻¹, i.v.) caused a fall in mean arterial blood pressure (MAP) from 116±4 to 77±5 mmHg. The pressor effect of phenylephrine (10 μg ml⁻¹, i.v.) was also significantly reduced at 30, 60, 120 and 180 min after LPS injection. In contrast, animals pretreated with andrographolide (1 mg kg⁻¹, i.v., 20 min prior to LPS) maintained a significantly higher MAP when compared to LPS-rats given with vehicle. Administration of andrographolide 60 min after LPS caused a increase in MAP and significantly reversed the reduction of the pressor response to phenylephrine.
6. Our results indicated that andrographolide inhibits nitrite synthesis by suppressing expression of iNOS protein in vitro. And, this inhibition of iNOS synthesis may contribute to the beneficial haemodynamic effects of andrographolide in endotoxic shock.

     

骨关节炎患者血清和关节液一氧化氮及其合成酶变化的意义

目的探讨骨关节炎(OA)患者血清及关节液中一氧化氮(NO)和诱生型一氧化氮合成酶(iNOS)与病情程度及活动性的关系.方法对30例轻度(n=7)、中度(n=12)、重度(n=11)骨关节炎患者及24例健康对照者血清及关节液中NO、iNOS、ESR、CRP的含量进行测定.结果中、重度骨关节炎组血清中NO、iNOS水平比健康组升高(P＜0.01);三组骨关节炎关节液中NO、iNOS水平均比对照组明显升高(P＜0.001);重度骨关节炎组血清中NO、iNOS水平与关节液中NO、iNOS水平呈正相关(r=0.589,P＜0.01);重度骨关节炎组关节液中NO、iNOS水平与ESR、CRP呈正相关(r=0.428,p＜0.05).结论iNOS及其产生的NO参与了OA的病变过程,是OA病程发展的重要机制.     

大鼠生后肾内皮型一氧化氮合酶的定量分析

为探讨内皮型一氧化氮合酶在大鼠生后肾发育中的作用,采用SD大鼠按生后年龄随机分为6组,即新生组、生后3天组、5天组、7天组、14天组和成年组,用免疫印记技术和光密度分析法对各组大鼠生后肾内皮型一氧化氮合酶进行定量检测,以测得的一氧化氮合酶最大量为1(100%),计算蛋白相对含量,SPSS10.0统计软件包统计分析。结果显示,新生组酶含量最高为1,随年龄增长酶含量逐渐减少,至第7天达到最少为44.60±2.41%,以后又增高至14天达成年水平为71.55±4.35%。提示大鼠生后不同年龄组肾内皮型一氧化氮合酶有明显的变化规律,NO可能在肾脏的成熟与发育中起重要作用。     

弥漫性颅脑损伤对大鼠海马一氧化氮合成酶活性及表达的影响

目的 :研究大鼠弥漫性颅脑损伤后海马结构一氧化氮合成酶 (NOS)活力及表达 ,分析海马不同亚区NOS活力变化与时间的关系。方法 :制作Wistar大鼠弥漫性脑损伤模型 ,并分对照组、假手术组及伤后6、12、24、48h组 ,于不同时间点获取脑组织 ;用NADPH 黄递酶 (NADPH d)组织化学法和免疫组化法检测NOS的活性及表达情况。结果 :NADPH d组织化学法显示 ,弥漫性脑损伤后 ,海马结构NOS阳性神经元数量在伤后6h最多 ,以后逐渐减少 ,伤后24、48h组明显低于假手术组 (P<0 05) ;免疫组化结果显示 ,在CA1、CA3区和齿状回 (DG) ,伤后24、48h组阳性细胞数均低于假手术组 (P<0 01)。结论 :大鼠弥漫性脑损伤后 ,可引起海马各区NOS的变化 ,该变化可能是造成脑组织继发性损害机制之一。     

NO和iNOS在大鼠糖尿病早期肾脏中的变化

目的:观察糖尿病大鼠早期肾脏中一氧化氮(Nitric oxide,NO)含量和诱导型一氧化氮合酶(Inducible nitric oxide syn-thase,iNOS)活性变化,探讨NO/iNOS在糖尿病早期肾脏损害中的作用机制。方法:取成年健康SD大鼠60只,随机分成糖尿病组(DM组)和正常对照组(NC组),每组30只。DM组大鼠采用一次性腹腔内注射STZ制造糖尿病大鼠模型,成模后和NC组分别于第1、2、4周麻醉取左肾,用硝酸还原酶法和吸光光度法测定肾组织中NO含量、一氧化氮合酶(nitric oxide synthase,NOS)和iNOS活性。所有数据用SPSS11.5统计软件进行统计学处理。结果:①DM组大鼠肾组织中NO含量、NOS和iNOS活性分别较同批NC组有显著性差异(P<0.05);②各组大鼠中NO含量与NOS活性、iNOS活性呈正相关。结论:糖尿病大鼠早期肾脏中iNOS活性增强,催化生成的NO在糖尿病早期肾脏损害中发挥重要作用。     

Biology,Chemistry and Therapeutic Applications of Nitric Oxide: First International Conference

The First International Conference on the Biology, Chemistry and Therapeutic Applications of Nitric Oxide represented a milestone in the history of nitric oxide (NO) research. This meeting combined the two major conferences on NO, the Biology of Nitric Oxide and the Biochemistry and Molecular Biology of Nitric Oxide. The conference was held at the Hyatt Regency Hotel in San Francisco under the auspices of the Nitric Oxide Society. This meeting successfully brought together scientists from all disciplines currently working in the field. There were three sessions on each day of the meeting, one session for each of the three areas (biology, chemistry and therapy). Each session consisted of two plenary lectures of 20 min duration followed by a series of short 10 min papers, with a total of 70 oral presentations. The meeting also included approximately 400 excellent poster presentations and a hot topics session. All the presentations and posters were of a very high standard and the conference chairs, J Parkinson and G Rubanyi and their co-chairs and scientific advisory board are to be congratulated on such an excellent programme. This review cannot begin to attempt to cover all the contributions, but only to convey the major themes and overall enthusiasm of the meeting. The interested reader is referred to the complete abstracts of the meeting which are published in Nitric Oxide, the journal of the Nitric Oxide Society [1].     

Nitric oxide modulates air embolism-induced lung injury in rats with normotension and hypertension

1. Air embolism the in lungs induces microvascular obstruction, mediator release and acute lung injury (ALI). Nitrite oxide (NO) plays protective and pathological roles in ALI produced by various causes, but its role in air embolism-induced ALI has not been fully investigated. 2. The purpose of the present investigation was to elucidate the involvement of NO and pro-inflammatory cytokines in the pathogenesis of ALI following air infusion into isolated perfused lungs from spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto (WKY) rats. 3. The extent of ALI was evaluated by changes in lung weight, Evans blue dye leakage, the protein concentration in the bronchoalveolar lavage and pathological examination. We also measured nitrite/nitrate (NO(x)), tumour necrosis factor (TNF)-alpha and interleukin (IL)-1beta concentrations in lung perfusate and determined cGMP in lung tissue. 4. The NO synthase (NOS) inhibitors N(G)-nitro-l-arginine methyl ester (l-NAME) and l-N(6)-(1-iminoethyl)-lysine (l-Nil), as well as the NO donors sodium nitroprusside (SNP) and s-nitroso-N-acetylpenicillamine (SNAP), were administered 30 min before air embolism at a concentration of 10(-3) mol/L in the lung perfusate. 5. Air embolism-induced ALI was enhanced by pretreatment with l-NAME or l-Nil, but was alleviated by SNP or SNAP pretreatment, in both SHR and WKY rats. In both SHR and WKY rats, AE elevated levels of NO(x) (2.6 and 28.7%, respectively), TNF-alpha (52.7 and 158.6%, respectively) and IL-1beta (108.4 and 224.1%, respectively) in the lung perfusate and cGMP levels in lung tissues (35.8 and 111.2%, respectively). Pretreatment with l-LAME or l-Nil exacerbated, whereas SNP or SNAP abrogated, the increases in these factors, except in the case of NO(x) (levels were decreased by l-LAME or l-Nil pretreatment and increased by SNP or SNAP pretreatment). 6. Air embolism caused increases in the lung weight (LW)/bodyweight ratio, LW gain, protein concentration in bronchoalveolar lavage and Evans blue dye leakage. These AE-induced changes were less in lungs isolated from SHR compared with normotensive WKY rats. 7. The results suggest that ALI and associated changes following air embolism in lungs isolated from SHR are less than those in WKY rats. Nitric oxide production through inducible NOS isoforms reduces air embolism-induced lung injury and associated changes. Spontaneously hypertensive rats appear to be more resistant than WKY rats to air embolism challenge.     

The effect of puerarin on serum nitric oxide concentration and myocardial eNOS expression in rats with myocardial infarction

Puerarin (1) is a major effective ingredient extracted from the traditional Chinese medicine Ge-gen (Radix Puerariae, RP). Recently, puerarin has been used to treat patients with coronary artery diseases (CAD). However, the mechanisms of puerarin on CAD are still not very clear. In this study, we investigated the role of puerarin on serum nitric oxide (NO) concentration, myocardial endothelial nitric oxide synthase (eNOS) gene expression, the protein expression of eNOS and inducible nitric oxide synthase (iNOS), as well as the level of protein kinase B (Akt/PKB) phosphorylation in rats with myocardial infarction. We found that puerarin (120 mg/kg/day, i.p.) could increase serum nitrite concentration in rat with myocardial ischemia (MI). It also induced the gene expression or activation of eNOS, protein expression of eNOS, and the Akt/PKB phosphorylation. From these results, we suggested that puerarin could increase serum nitric oxide level of rat with myocardial infarction, which should be one of the mechanisms of the therapeutic effect of puerarin on CAD. The increased expression of eNOS and the Akt/PKB pathway may be the underlying mechanism by which puerarin stimulates NO production.