ARDS时HO抗氧化作用机制初探

目的 探讨血红素氧合酶(HO)抗氧化性对急性呼吸窘迫综合征(ARDS)的保护作用及其机制。方法 采用电子自旋共振(ESR)技术直接测量活性氧(ROS),并结合化学发光法和脂质过氧化产物测定等技术来研究ARDS发生发展过程中HO对自由基的影响。结果 ESR结果显示,大鼠注射OA后10min ROS含量即升高,30min达到高峰,以后逐渐下降;HO组未见ROS显著增加;而化学发光法定量检测和SOD检测结果与ESR波谱显示的结果完全一致,MDA从检测结果则提示Hb诱导HO有一定的副作用。结论 ROS可能是ARDS启动的主要病因;HO有一定的抗氧化能力。     

丹参对大鼠化学性ARDS的防治作用

目的 探讨丹参对化学性急性呼吸窘迫综合征(ARDS)的防治作用及可能机制。方法 经股静脉注射油酸复制大鼠ARDS模型,应用电子自旋共振(ESR)技术观察大鼠肺内活性氧(ROS)自由基的生成情况,同时检测血浆丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性的变化,进行肺湿干重、肺系数测定及肺组织病理学检查,并与使用丹参组大鼠结果进行比较。结果 丹参组ARDS大鼠肺内ROS含量显著降低,SOD活力升高,MDA生成减少,肺湿干重、肺系数及病理学指标亦得到显著改善。结论 丹参对化学性ARDS具有防治作用,其机制之一与减少体内活性氧自由基的生成有关。     

牛磺酸对大鼠化学性急性呼吸窘迫综合征防治作用的实验研究

目的探讨牛磺酸对化学性急性呼吸窘迫综合征(ARDS)的防治作用及可能机制。方法经股静脉注射油酸复制大鼠ARDS模型,应用电子自旋共振(ESR)技术观察大鼠肺内活性氧(ROS)自由基的生成情况,观察血浆丙二醛(MDA)含量和超氧化物歧化酶(SOD)活力的变化,进行肺湿干重、肺系数测定及肺组织病理学检查。结果牛磺酸组大鼠肺湿干重、肺系数及病理学指标皆得到显著改善,并且高剂量用药效果更佳。研究显示牛磺酸可显著降低ARDS大鼠肺内ROS含量,抑制组织脂质过氧化的发生,提高SOD活力。结论牛磺酸对化学性ARDS具有防治作用,其机制之一与减少体内活性氧自由基的生成有关。     

维生素C和谷胱甘肽对离体肺泡巨噬细胞超微弱发光的影响

目的　研究外源维生素 C(VC)和谷胱甘肽 (GSH)对家兔离体肺泡巨噬细胞(AM)超微弱 (自主 )发光的影响。方法　将 AM悬浮在含有 VC或 GSH的 DMEM培养介质中 ,放入一特制恒温箱的培养盒内 ,连续通入不同浓度的氧气 ,用发光仪检测培养 AM的超微弱发光。结果　浓度超过 0 .3mmol/L的 VC能明显增强有氧培养细胞超微弱发光和加速细胞死亡 ,对无氧培养细胞的影响不明显。低浓度 (0 .0 3mmol/L) VC与 GSH相同 ,能降低由高浓度 (99.1 % )氧暴露引起的细胞发光增强。结论　细胞在含氧气体中的自发氧化是产生超微弱发光的重要原因 ;高浓度 VC能促进离体细胞氧化损伤 ,GSH则有抗氧化作用。     

松果菊苷对大鼠急性肺损伤模型早期干预作用研究

目的 探索大鼠急性肺损伤/急性呼吸窘迫综合征(ALI/ARDS)的自由基变化及早期应用自由基清除剂松果菊苷(ECH)的防护作用.方法 本研究分设4个研究组:对照组、ECH组、油酸(OA)组、OA-ECH组,分别在5个时间点采取标本检测动脉血气、肺组织活性氧(ROS)信号、肺湿/干重比值和肺病理.结果 在各组中ALI的程度与自由基的相对浓度具有一致性,自由基的改变(30 min)明显早于肺组织病理学(2 h)改变.在注射OA后2 h,OA组肺自由基达130～140高斯(Gauss),氧分压降至45～55 mmHg;而OA-ECH组自由基是70～80 Gauss,氧分压在65～75 mmHg.肺湿/干重比值和病理学评分在2组差异也有统计学意义(P＜0.01).ECH通过减少ROS的生成,可明显减轻ALI的病理改变和低氧血症.结论 ROS是ALI发病过程的启动因子,早期应用抗氧化剂ECH可在一定程度上改善ALI的预后.     

丹参总酚酸对兔急性呼吸窘迫综合征时心功能的影响

目的探讨丹参总酚酸对兔急性肺损伤/急性呼吸窘迫综合征(ALI/ARDS)时心功能的影响及其可能机制。方法新西兰兔24只,分为对照组、ALI/ARDS组和丹参总酚酸干预组;经颈静脉注射油酸(OA,0.15mg/kg)复制兔ALI/ARDS模型,颈动脉插管至左心室,随时记录左室收缩末期压力(LVSP)、收缩末期左心室压力最大上升速率(+dp/dtmax)、舒张末期左心室压力最大下降速率(-dp/dtmax),开胸分离胸主动脉根部,套以内径适宜的电磁流量计探头,备测心输出量(CO),肺动脉根部插管备测平均肺动脉压(mPAP)。丹参总酚酸组于注OA前30min静脉注射丹参总酚酸(10mg/kg);各组于注OA后10、30、60、120min采血测定血浆丙二醛(MDA)含量,2h后取肺做病理检查。结果ALI/ARDS组兔在注射OA后10、30、60、120min各时间点,血浆MDA水平均显著高于对照组(P<0.01或P<0.05);注射OA后10min,CO开始降低,mPAP即见升高;至60min、120min时,+dp/dtmax和-dp/dtmax方明显低于对照组(P<0.01)。丹参总酚酸干预组与ALI/ARDS组比较,各时间点血浆MDA水平均见降低,而左心室功能于注射OA后60min、120min时则显著高于ALI/ARDS组(P<0.05),且与对照组比较差异无显著性(P>0.05)。结论ALI/ARDS兔存在心功能障碍,mPAP升高可能为其始动环节,可依次导致右心或左心功能降低;丹参总酚酸有助于改善心脏功能,其机制可能与其抗氧化功能有关。     

骨关节病与细胞外基质中胶原基因的改变

骨关节病(OA)的病因目前尚不清楚,随着分子生物学技术的进一步发展,人们已经注意到环境因素和遗传因素的交互作用在骨关节病中的可能作用。结合目前的研究现状,主要从Ⅰ、Ⅸ、Ⅹ、Ⅺ型胶原的基因改变对骨关节病的影响作了综述,认为软骨特异性胶原基因的变异可能在OA中起关键作用,为进一步探讨骨关节病及大骨节病的发病机理提供新的思路。     

基于流动注射技术的电化学发光分析体系的研究

目的：探讨一种新的电化学发光分析方法,为临床多肿瘤标志物的联合检测进行前期研究。方法：采用流动注射法进样,用循环伏安法进行电化学分析,通过化学发光图谱考察所建立体系的响应特性。结果：这种基于流动注射分析技术的电化学发光分析体系的灵敏度可达5×10^-8mol／L,高于高压电场进样的毛细管电化学发光分析体系。结论：流动注射电化学发光法的检测灵敏度优于毛细管电泳电化学发光分析法,具有一定的应用前景。     

西红花酸抗氧化干预脂肪肝细胞的研究

目的探讨西红花酸对于非酒精性脂肪肝细胞的干预作用及其作用机制。方法 :采用油酸和棕榈酸的脂肪酸混合液诱导L02肝细胞株,建立非酒精性脂肪肝模型,并加入一定浓度的西红花酸进行干预。通过观察细胞形态,甲基噻唑基四唑(MTT)法检测细胞活力,并检测细胞内三酰甘油(TG)含量,以及细胞内氧化还原指标包括谷胱甘肽(GSH)、还原型辅酶Ⅱ(NADPH)、超氧化物歧化酶(SOD)、活性氧(ROS)和丙二醛(MDA)水平,以反映西红花酸对脂肪肝细胞模型的干预作用。结果使用西红花酸后脂肪肝细胞中TG含量降低,细胞中脂质沉积有效缓解,ROS、MDA水平呈明显下降,且NADPH,GSH,SOD等抗氧化系统指标明显改善。结论西红花酸通过降低脂肪肝细胞内氧化应激水平可能对脂肪肝防治有一定作用。     

铅对作业工人红细胞超氧化物歧化酶影响的研究

人体内超氧化物歧化酶（superoxi dedisumutase，SOD）的主要作用是催化超氧化物阴离子自由基（O2^-）发生歧化反应。已有研究表明，超氧离子自由基可促进机体发生脂质过氧化对机体产生毒害作用，而SOD起清除自由基的作用，起到抗氧化、抗衰老、抗肿瘤和炎症及辐射操作等方面的重要作用。它是生物抗氧化系统的主要酶。     

葡多酚对活性氧自由基的清除作用研究

目的 :　探讨葡多酚 ( GPC)对活性氧自由基的清除作用。方法 :　采用电子自旋共振 ( ESR)和自旋捕集技术直接测定不同浓度 GPC对 Fenton反应体系产生的羟自由基 (· OH)、光照核黄素 /EDTA体系产生的超氧阴离子 ( O·2 )及 Fe2 + 启动线粒体膜脂质过氧化产生的脂类自由基 ( LOO· )清除作用。结果 :　 GPC浓度为 1 mg/L、1 0 mg/L、1 0 0 mg/L、1 0 0 0 mg/L对·OH的清除率 ( % )依次为 9.0、2 0 .6、47.7、57.7,对 O·2 的清除率 ( % )分别为 1 0 .9、1 7.0、50 .9、72 .1 ,对LOO·的清除率 ( % )依次为 39.8、49.6、65.9、71 .4。葡多酚对· OH、O·2 及 LOO· 50 %的清除浓度 ( IC50 值 )分别为 1 2 8.9mg/L、89.4mg/L、1 0 .4mg/L。结论 :　葡多酚对三种活性氧自由基均有不同程度的清除作用 ,其中 LOO· >O·2 >· OH。     

Reactive oxygen species and anti-oxidant defences in swine follicular fluids

A growing body of evidence indicates that the pro-oxidant/anti-oxidant balance inside the ovarian follicle plays an important role in folliculogenesis. Therefore, the aim of the present study was to assess the redox status of follicular fluids collected from different-sized swine follicles. We quantified the most important reactive oxygen species (ROS), namely superoxide anion (O(2)(-)), hydrogen peroxide and hydroperoxides (ROOH); in addition, we examined the activity of the detoxifying enzymes superoxide dismutase, catalase (CAT) and glutathione peroxidase and the total non-enzymatic antioxidant capacity as determined by the ferric-reducing anti-oxidant power assay. Our data demonstrate that oxidative stress does not affect follicle growth because O(2)(-) levels do not change during follicle development, whereas concentrations of H2O2 and ROOH are reduced (P < 0.05). Surprisingly, all non-enzymatic and enzymatic scavengers examined in the present study, except for CAT, demonstrated reduced activity during follicle development (P < 0.05). Taken together, these results suggest that other factors could be involved in ROS detoxification during follicle development.     

Evaluation of antioxidant properties of a new compound, pyrogallol-phloroglucinol-6,6'-bieckol isolated from brown algae, Ecklonia cava

In this study, antioxidant and free radical scavenging activities of the natural antioxidative compound, pyrogallol-phloroglucinol-6,6''-bieckol (PPB) isolated from brown algae, Ecklonia cava was assessed in vitro by measuring the radical scavenging activities (DPPH, alkyl, hydroxyl, and superoxide) using electron spin resonance (ESR) spectrometry, intracellular reactive oxygen species (ROS) scavenging activity, and DNA damage assay. According to the results of these experiments, the scavenging activity PPB against difference radicals was in the following order: DPPH, alkyl, hydroxyl, and superoxide radicals (IC₅₀; 0.90, 2.54, 62.93 and 109.05 µM). The antioxidant activities of PPB were higher than that of the commercial antioxidant, ascorbic acid. Furthermore, PPB effectively inhibited DNA damage induced by H₂O₂. These results suggest that the natural antioxidative compound, PPB, can be used by the natural food industry.     

Antioxidant properties of Viburnum opulus and Viburnum lantana growing in Turkey

In the present study, antioxidant properties of the water extracts of different parts of Viburnum opulus and Viburnum lantana (Caprifoliaceae) were investigated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging and superoxide anion scavenging methods. The extracts were prepared from the fruits, branches, and leaves of V lantana and V opulus species. The branch extracts of V lantana and V opulus inhibited superoxide anion in a concentration-dependent manner. Compared with t-tocopherol, the fruit extract of V lantana did not show any scavenging effect on superoxide anion formation. V lantana leaf extracts, however, showed a moderate scavenging effect on superoxide anion formation, whereas V lantana branch extracts showed a strong scavenging effect (IC50 = 3.1 mg/ml) on superoxide anion in higher concentration. On the other hand, all extracts exhibited a scavenging effect on the DPPH radical with various potencies. When compared with butylated hydroxytoluene, V opulus branch and V lantana leaf extracts, as well as V lantana branch, V opulus fruit and V lantana fruit extracts, showed strong DPPH radical scavenging activity with IC50 values of 0.014, 0.035, 0.052, 0.057 and 0.085 mg/ml, respectively.     

Antioxidative activity of hen egg ovalbumin hydrolysates

To evaluate the antioxidative activity of the hydrolysates of ovalbumin, the antioxidative activities of the enzymatic extracts were evaluated using three different methodologies scavenging assays such as superoxide anion, hydroxyl radical, and inhibitory oxidation of linoleic acid in vitro, and the activities of SOD, GSH-PX, CAT and the level of MDA were determined in serum and liver of aged mice induced by G-gal. The results showed that the hydrolysates had a distinctly inhibitory action to superoxide anion made by alkaline pyrogallic acid, HO. produced by Fenton reaction, the oxidation of linoleic acid in linoleic acid autoxidation system, and presented a positive correlation. The inhibition capacity of hydrolysates against superoxide anion and HO. were more than 45% and 56% respectively at the concentration 5 mg/mL. And the hydrolysates could significantly (p< 0.01) prevented the activities of SOD, GSH-Px, and CAT against reducing and all three concentrations could significantly (p< 0.01) decrease the MDA contents in the serum and liver of aged mice induced by G-gal. The antioxidative activity of high concentration was similar to that of control group.     

褐藻硫酸多糖铁配合物的稳定性及其清除自由基的作用

目的对褐藻硫酸多糖(SP)和SP作为配体合成的一种新型的功能性补铁剂褐藻硫酸多糖铁复合物(SPIC)的理化性质、结构组成,以及自由基清除能力做了对比研究。方法通过SP与Fe(Ⅲ)在适当浓度和条件下络合生成SPIC,用苯酚法测定SP和SPIC的总多糖含量、Hodgson法测定二者的硫酸根含量和Folin酚试剂法测定蛋白含量,红外光谱分析结构,以及电子自旋共振(ESR)结合自旋捕捉检测二者对自由基的清除作用。结果SP与SPIC都具有很好的稳定性且二者的多糖含量相当,而SPIC中蛋白质含量较SP中低,硫酸根含量约为SP的1/2,Fe(Ⅲ)的含量为21.22%。红外光谱分析,可以鉴别SPIC含有稳定的FeOOH核的类型。二者都有清除自由基的作用,但SPIC对超氧自由基的清除作用更强,而对羟自由基清除作用减弱。结论SPIC中铁的络合,有可能达到既补铁,又发挥SP可清除自由基抗氧化功能的双重作用。     

Role of Nitric Oxide and Peroxynitrite in Bile Salt-Induced Apoptosis: Relevance to Colon Carcinogenesis

Previous work from our laboratory indicated that the bile salt sodium deoxycholate (NaDOC) induced apoptosis in cultured cells and in normal goblet cells of the colonic mucosa. We also reported that the normal-appearing flat mucosa of patients with colon cancer exhibited apoptosis resistance. Using immunofluorescence in conjunction with confocal microscopy, we now report that high physiological concentrations (0.5 mM) of NaDOC result in the formation of nitrotyrosine residues, a footprint for the formation of reactive nitrogen species, including peroxynitrite, in plasma membrane-associated proteins of HT-29 cells. Because peroxynitrite is formed from the reaction between nitric oxide and superoxide anion, we specifically looked at the role of nitric oxide and superoxide anion in NaDOC-induced apoptosis. Pretreatment of cells with the inhibitor/antioxidants, N-nitro-L-arginine methyl ester, an inhibitor of nitric oxide synthase, copper (II) 3,5-diisopropyl salicylate hydrate, a superoxide dismutase mimetic com-pound, and Trolox, a water-soluble analog of a -tocopherol, alone or in combination, sensitized cells to apoptosis in-duced by 0.5 mM NaDOC. These results suggest that nitric oxide may be part of a signaling pathway that is responsible for apoptosis resistance. The results also indicate that nitric oxide does not appear to protect cells against NaDOC-induced apoptosis by scavenging superoxide anion.