脂联素通过减轻氧化应激治疗动脉粥样硬化的研究

观察不同滴度的脂联素腺病毒载体对高脂饮食载脂蛋白E基因敲除小鼠动脉粥样硬化模型的影响,以探讨脂联素抗动脉粥样硬化（AS）是否与减轻氧化应激有关。将48只健康成年12周龄载脂蛋白E基因敲除小鼠随机分为4组,对照组,模型组,低剂量脂联素组,高剂量脂联素组。对照组给予正常饮食8周;模型组给予高脂饮食8周;低剂量脂联素组每两周经尾静脉注射脂联素腺病毒载体1．0×108p．f．u,实验期间高脂饮食;高剂量脂联素组每两周经尾静脉注射脂联素腺病毒载体5．0×108p．f．u．实验期间高脂饮食。实验结束后,摘眼球采血取血清,测定总胆固醇（TC）,甘油三酯（TG）,低密度脂蛋白（LDL-C）,高密度脂蛋白（HDL-C）,以及血清脂联素（APN）含量,超氧化物歧化酶（SOD）活性,丙二醛（,MDA）含量,取小鼠主动脉血管。实时荧光定量扩增法（RT-PCR）测定小鼠主动脉血管APN,内皮型一氧化氮合酶（eNOS）的表达。与模型组比较,外源性的脂联素降低了血清TG,TC,LDL-C,MDA的含量,血清SOD活性增加,上调动脉血管中APN和eNOS的表达。AS损伤面积明显减少,分别降低了26％和31％（P＜0．05）,脂纹区的脂滴直径降低极显著（P＜0．01）,随着APN剂量的增加,AS损伤逐步减轻,但是低剂量脂联素组和高剂量脂联素组的差异没有统计学意义。减轻氧化应激是脂联素抑制动脉粥样硬化的一种保护机制和途径。     

bFGF对左旋硝基精氨酸诱导大鼠高血压的影响

本文观察了ｂＦＧＦ对Ｌ－ＮＮＡ诱导的大鼠高血压形成的影响及其机制。结果发现：（１）ｂＦＧＦ使高血压大鼠的平均动脉压较单纯高血压动物的血压降低３．８ｋＰａ（ｐ＜０。０５）;主动脉对乙酰胆碱（ＡＣｈ）的最大舒张反应增加６４．２％（Ｐ＜０．０１）：（２）注射ｂＦＧＦ使高血压大鼠血浆及主动脉薄片孵育液中的亚硝酸盐（ＮＯ２－）含量均显著增高,并明显恢复了血管薄片对ＡＣｈ刺激的敏感性;（３）ＭＧＦ使高血压大鼠血管壁的ｔＮＯＳ、ｉＮＯＳ及ｃＮＯＳ含量分别较单纯高血压大鼠的增加２５．５％、１５．６％和４５．７％（Ｐ＜０．０５或Ｐ＜０．０１）。结果提示：ｂＦＧＦ具有明显的拮抗Ｌ－ＮＮＡ诱导的高血压形成的作用,其机理与刺激血管壁ＮＯＳ活性、增加ＮＯ的产生有关。     

Arginase Inhibition Restores Peroxynitrite-Induced Endothelial Dysfunction via L-Arginine-Dependent Endothelial Nitric Oxide Synthase Phosphorylation

PurposePeroxynitrite plays a critical role in vascular pathophysiology by increasing arginase activity and decreasing endothelial nitric oxide synthase (eNOS) activity. Therefore, the aims of this study were to investigate whether arginase inhibition and L-arginine supplement could restore peroxynitrite-induced endothelial dysfunction and determine the involved mechanism.ResultsSIN-1 treatment increased arginase activity in a time- and dose-dependent manner and reciprocally decreased nitrite/nitrate production that was prevented by peroxynitrite scavenger in HUVECs. Furthermore, SIN-1 induced an increase in the expression level of arginase I and II, though not in eNOS protein. The decreased eNOS phosphorylation at Ser1177 and the increased at Thr495 by SIN-1 were restored with arginase inhibitor and L-arginine. The changed eNOS phosphorylation was consistent in the stability of eNOS dimers. SIN-1 decreased NO production and increased ROS generation in the aortic endothelium, all of which was reversed by arginase inhibitor or L-arginine. N^G-Nitro-L-arginine methyl ester (L-NAME) prevented SIN-1-induced ROS generation. In the vascular tension assay, SIN-1 enhanced vasoconstrictor responses to U46619 and attenuated vasorelaxant responses to acetylcholine that were reversed by arginase inhibition.ConclusionThese findings may explain the beneficial effect of arginase inhibition and L-arginine supplement on endothelial dysfunction under redox imbalance-dependent pathophysiological conditions.     

Oxidative Stress is Increased in Serum from Mexican Patients with Relapsing-Remitting Multiple Sclerosis

Objective: To determine the oxidative stress markers in serum from patients with relapsing-remitting multiple sclerosis. Methods: Blood samples from healthy controls and 22 patients 15 women (7 aged from 20 to 30 and 8 were > 40 years old) and 7 men (5 aged from 20 to 30 and 2 were > 40 years old) fulfilling the McDonald Criteria and classified as having Relapsing-Remitting Multiple Sclerosis accordingly with Lublin were collected for oxidative stress markers quantification. Results: Nitric oxide metabolites (nitrates/nitrites), lipid peroxidation products (malondialdehyde plus 4-hidroxialkenals), and glutathione peroxidase activity were significantly increased in serum of subjects with relapsing-remitting multiple sclerosis in comparison with that of healthy controls. These data support the hypothesis that multiple sclerosis is a component closely linked to oxidative stress.     

Hydrogen Peroxide Production and Free Radical-mediated Cell Stress in Mycoplasma bovis Pneumonia

Mycoplasma bovis isolates produce H₂O₂, and oxidative and nitrative injury are detected in infected lung tissue.

1. Download : Download high-res image (211KB)
2. Download : Download full-size image

     

连翘苷对肥胖症大鼠脂代谢紊乱和氧化应激的影响及机制研究

目的 探究连翘苷对肥胖症大鼠模型脂代谢紊乱和氧化应激的影响。 方法 采用高脂饲料喂养 建立肥胖症大鼠模型 (将大鼠随机分为 6 组: 对照组、 模型组、 连翘苷 5 mg / kg 组、 连翘苷 10 mg / kg 组、 连翘苷 20 mg / kg 组和二甲双胍组); 检测大鼠体重; 卷尺测量肛鼻长计算 Lee’s 指数; 血糖仪检测血糖水 平; 油红 O 染色检测脂质蓄积程度; 全自动生化分析仪检测 TC、 TG、 LDL-C 和 HDL-C 水平; 试剂盒检测 ALT、 AST、 ALP 水平和 SOD、 MDA、 GSH-Px 含量。 Western 印迹检测 p-Nrf2、 Nrf2、 HO-1 蛋白表达水平。 结果 与对照组相比较, 模型组 Lee’s 指数、 体重增重和血糖水平升高, TC、 TG 和 LDL-C 水平升高, HDL-C 水平降低, ALT、 AST 和 ALP 水平升高, SOD、 GSH-Px 含量降低, MDA 含量升高, p-Nrf2 / Nrf2、 HO-1 蛋白表达水平降低, 差异具有统计学意义 (P< 0. 05)。 与模型组相比较, 连翘苷 10、 20 mg / kg 组和 二甲双胍组 Lee’s 指数、 体重增重和血糖水平降低, 脂质蓄积程度明显改善, TC、 TG 和 LDL-C 水平降低, HDL-C 水平升高, ALT、 AST 和 ALP 水平降低, SOD、 GSH-Px 含量升高, MDA 含量降低, p-Nrf2 / Nrf2、 HO-1 蛋白表达水平升高, 差异具有统计学意义 (P< 0. 05)。 结论 连翘苷可改善肥胖症大鼠模型氧化应激 及脂代谢紊乱, 这可能是通过活化 Nrf2 / HO-1 信号通路实现的。     

被动吸烟对大鼠脑组织iNOS表达的影响

目的　研究被动吸烟大鼠脑组织诱发型一氧化氮合酶 (iNOS)的变化 ,探讨iNOS在吸烟导致脑损伤中的作用机制。方法　制备被动吸烟大鼠模型 ,采用免疫组织化学ABC方法检测脑组织iNOS表达 ,应用光镜、透射电镜观察海马神经元的病理改变。结果　正常对照组大鼠大脑皮层、海马、纹状体均有少量iN OS表达 ,短期吸烟组与正常对照组比较有显著差异 (P <0 0 1) ,长期小量或大量吸烟组 (3个月 )各脑区iN OS表达显著高于正常对照组和短期吸烟组 (P<0 0 1)。长期大量吸烟组可见海马神经元变性改变。结论　吸烟可使脑组织iNOS活化表达增强生成过多的NO造成脑神经细胞毒性损伤 ,存在量效、时效关系。     

噪声对大鼠学习记忆中海马区NOS阳性神经元表达的影响

目的：拟在白噪声下观察对大鼠学习记忆的影响及海马区NOS的变化，探讨噪声所致大鼠学习记忆下降的机制。方法：44只SD大鼠，其中20只随机分两组，分别在持续80dB(A)白噪声和无噪声的环境下，在Y—迷宫中进行空间辨别学习记忆训练，了解噪声对大鼠学习记忆的影响，另24只大鼠随机分三组：噪声训练组、正常训练组和噪声观察组，以同样的方法训练，用免疫组化的方法观察持续噪声对海马区NOS阳性神经元表达变化。结果：噪声能降低大鼠学习记忆能力，而且海马区NOS阳性神经元较正常对照组的数量及染色强度显著降低。结论：噪声降低海马区神经元活性，NOS的合成减少，抑制海马习得性长时程突触增强，影响记忆的获得与保持，延迟短时记亿向长时记忆的转化。     

束缚应激对大鼠血小板-氧化氮释放的影响

目的 观察急性应激对大鼠血小板一氧化氮(NO)释放的影响及其机制.方法 大鼠浸水-束缚应激(WRS)2、4和8 h,以胃溃疡指数(UI)作为应激损伤的标识,采用Greiss法测定血小板孵育液中亚硝酸盐(NO2-)含量;同位素法测其一氧化氮合酶(NOS)活性和L精氨酸(L-Arg)转运量.结果 WRS 2 h血小板L-Arg转运量、NOS活性和孵育液NO2-含量较对照组显著增加,但随应激时间延长,其呈下降趋势,应激8 h时均显著低于对照组,胃溃疡逐渐加重.结论 WRS应激早期阶段可上调血小板L-Arg/NO通路,促进血小板NO生成;长时间应激下调L-Arg/NO通路,减少NO释放.     

参芪汤对糖尿病大鼠勃起功能的影响

目的　探讨参芪汤对雄性糖尿病大鼠勃起功能的作用。方法　48只Wistar大鼠随机分为正常 对照组(NC组);糖尿病组(DM组),链脲佐菌素60mg/kg腹腔注射;中药治疗组(DD组),参芪汤17.7g· kg-1·d-1灌胃。检测各组第8周的血糖、阴茎勃起潜伏期、酶组化及图象分析观察阴茎海绵体中一氧化氮合 酶(NOS)和球海绵体肌中乙酰胆碱酯酶(AchE)的活性。结果　DD组的血糖略低于DM组,无差异(P> 0.05)。DD组阴茎勃起潜伏期明显短于DM组,差异显著(P<0.05)。DD组的NOS、AchE的阳性反应显著 强于DM组,差异显著(P<0.05)。DD组的勃起潜伏期、NOS、AchE阳性反应与正常组接近。结论　参芪汤 可能通过增加NOS和AchE活性,发挥改善阴茎勃起功能的作用。     

急性酒精中毒对老龄大鼠纹状体NO和nNOS及学习记忆的影响

目的通过观察急性酒精中毒对老龄大鼠学习记忆的影响并测定脑纹状体组织中一氧化氮(NO)与神经型一氧化氮合酶(nNOS)含量的变化,探讨酒精中毒影响学习记忆的分子机制。方法老龄(Sprague-Dawley,S-D)大鼠购回后适应性饲养两天,随机分为2组,酒精组腹腔一次性注射乙醇2.5g/kg[用生理盐水配成含20%乙醇(w/v)溶液]制备急性酒精中毒大鼠模型;对照组注射等容量的生理盐水。Y-型迷宫检测大鼠学习记忆成绩、硝酸还原酶法检测鼠脑纹状体中NO的含量、免疫组化方法检测鼠脑纹状体中nNOS的含量。结果(1)酒精组大鼠达到学会标准所需要的训练次数(36.46±12.23)明显大于对照组(28.49±9.32),P<0.05;(2)纹状体NO的含量在酒精组为22.31±8.78,对照组为9.67±4.77,前者明显高于后者(P<0.01);(3)纹状体nNOS阳性神经元的数量在酒精组为10.40±4.47,对照组为5.30±3.25,前者明显高于后者(P<0.05)。结论上述结果提示酒精的神经毒性作用可能与脑纹状体组织中nNOS和NO信号通路有关。     

Efficacy of Royal Jelly on Methotrexate-Induced Systemic Oxidative Stress and Damage to Small Intestine in Rats

The aim of this present study is to investigate the mucositis caused by methotrexate (MTX), as well as whether the application of royal jelly (RJ) has a protective effect on oxidative stress. This present study included six groups each consisted of 12 Wistar rats. Distilled water (po: peroral) was given to the 1^st group as placebo for 10 days and MTX (20 mg/kg, intraperitoneal: ip) on the 7^th day. The 2^nd group received RJ (50mg/kg, po) for 10 days and normal saline (NS) instead of MTX. RJ (50mg/kg) was given to the 3^rd group for 10 days and MTX on the 7^th day. The 4^th group received RJ (100 mg/kg, po) for 10 days and NS was given intraperitoneally. RJ (100mg/kg) was given to the 5^th group for 10 days and a single dose of MTX. Distilled water was given to the 6^th (control) group for 10 days and intraperitoneal NS on the 7^th day. Malondialdehyde (MDA), glutathione peroxidase and superoxide dismutase were analyzed in blood samples on the 11^th day. Morphological and histopathological changes were examined in the intestinal tissue samples. Villus length and mucosal thickness, as well as the villus length/crypt ratio, were significantly decreased with MTX administration, and the semi-quantitative histological evaluation (SQHE) score was measured high (p<0.001). In addition, a decrease in the antioxidant parameters and an increase in the MDA levels were identified. The villus length and SQHE were significantly different in the groups receiving RJ (p<0.001) as compared to the MTX group. Although RJ addition had no effect on the decreased mucosal thickness and villus/crypt ratio in MTX groups, it caused an improvement in the antioxidant levels and a remarkable decrease in MDA levels. Adding RJ has a decreasing effect on the MTX-induced intestinal damage and it has a suppressive effect on MTX-induced oxidative stress by means of increasing antioxidant enzyme activity and decreasing lipid peroxidation.     

银杏叶提取物联合盐酸文拉法辛对抑郁大鼠海马nNOS蛋白表达及NO水平的影响

目的 :探讨抑郁症脑损伤的机制 ,研究银杏叶提取物 (EGb)及合成抗抑郁药盐酸文拉法辛(Venlafaxine)对抑郁大鼠的抗脑损伤及神经元保护作用。方法 :慢性应激建立大鼠抑郁模型。将 84只雄性大鼠分为正常对照组、抑郁模型组和不同治疗组。快速断头法处死 ,取海马后一侧进行免疫组化反应 ,观察海马CA3区nNOS蛋白的表达 ;另一侧检测NO含量 ;同时测定血清中NO含量。结果 :抑郁模型组海马nNOS表达增加 ,海马及血清中NO含量增加 ,P <0 0 1;联合用药组海马nNOS表达下降 ,海马及血清中NO含量减少 ,P <0 0 1。结论 :慢性应激增加海马nNOS表达 ;EGb有减轻神经元损伤 ,保护神经元的作用 ,其与Venlafaxine合用可能会达到对抑郁进行多靶点、多层次的治疗 ,弥补单一用药的不足。     

慢性应激对大鼠空间学习记忆和海马一氧化氮的影响

目的 :探讨慢性应激对大鼠空间学习记忆和海马NO的影响。方法 :采用电击足底结合噪声建立慢性应激大鼠模型 ,Morris水迷宫观察动物的学习和记忆能力 ,同时检测海马NO含量和NOS活性。结果 :慢性应激大鼠在Morris水迷宫的空间学习和记忆能力明显下降 ,海马NO含量和NOS活性 (3 87± 0 47nmol/mgpro和 10 2 64± 13 33pmol/mgpro/min)显著高于对照组大鼠 (2 76± 0 43nmol/mgpro和 78 2 5± 10 67pmol/mgpro/min)。结论 :慢性应激损害大鼠空间学习和记忆能力 ,可能与其海马内NO增多有关     

氧化苦参碱对胎龄新生大鼠代谢综合征氧化应激和糖脂代谢的调节

目的 探索氧化苦参碱对胎龄新生大鼠代谢综合征氧化应激和糖脂代谢的影响及其作用机制.方法 建立新生胎龄大鼠代谢综合征模型,检测血糖、 胰岛素、 血脂、 肥胖指数、 氧化应激水平和肝脏脂肪变性程度,检测AMPK、SIRT1、PGC1α蛋白表达.加入AMPK抑制剂后再次检测上述指标变化.结果 与MS组比,各氧化苦参碱剂量组大...     

Antioxidant mediated response of Scoparia dulcis in noise induced redox imbalance and immunohistochemical changes in rat brain

Noise has been regarded as an environmental/occupational stressor that causes damages to both auditory and nonauditory organs. Prolonged exposure to these mediators of stress has often resulted in detrimental effect, where oxidative/nitrosative stress plays a major role. Hence, it would be appropriate to examine the possible role of free radicals in brain discrete regions and the "antioxidants" mediated response of S. dulcis. Animals were subjected to noise stress for 15 days (100 dB/4 hours/day) and estimation of endogenous free radical and antioxidant activity were carried out on brain discrete regions (the cerebral cortex, cerebellum, brainstem, striatum, hippocampus and hypothalamus). The result showed that exposure to noise could alleviate endogenous free radical generation and altered antioxidant status in brain discrete regions when compared to that of the control groups. This alleviated free radical generation (H2O2 and NO) is well supported by an upregulated protein expression on immunohistochemistry of both iNOS and nNOS in the cerebral cortex on exposure to noise stress. These findings suggest that increased free radical generation and altered anti-oxidative status can cause redox imbalance in the brain discrete regions. However, free radical scavenging activity of the plant was evident as the noise exposed group treated with S. dulcis[200 mg/(kg $b$w)] displayed a therapeutic effect by decreasing the free radical level and regulate the anti-oxidative status to that of control animals. Hence, it can be concluded that the efficacy of S. dulcis could be attributed to its free radical scavenging activity and anti-oxidative property.     

褪黑素对糖尿病周围神经病变大鼠氧化应激的作用

研究褪黑素(melatonin,MEL)对糖尿病周围神经病变(diabetic peripheral neuropathy,DPN)大鼠氧化应激和神经功能及形态学的影响,并与抗氧化剂硫辛酸进行比较。链脲佐菌素诱导糖尿病(DM)大鼠模型,维持饲养8周后随机分为4组:DM对照组、褪黑素小剂量治疗组(0.5 mg.kg-1.d-1)、褪黑素大剂量治疗组(10mg.kg-1.d-1)、硫辛酸治疗组(100mg.kg-1.d-1)。造模前预设鼠龄和体重相当的正常对照组8只。MEL和硫辛酸干预治疗8周后检测各组大鼠血浆和坐骨神经抗氧化酶活性和胆质过氧化产物含量的变化,大鼠摆尾阈值、坐骨神经超微结构和神经传导速度的变化。结果显示,DM对照组大鼠血浆和坐骨神经中丙二醛(MDA)含量明显增加,超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性显著降低,摆尾阈值提高,坐骨神经传导速度降低,坐骨神经出现脱髓鞘以及轴突萎缩等病理变化。MEL和硫辛酸均可显著改善上述变化。DM时自由基的损伤和抗氧化能力的降低可能在DPN的发生发展中发挥重要作用。     

Piper Sarmentosum Increases Nitric Oxide Production in Oxidative Stress: A Study on Human Umbilical Vein Endothelial Cells

OBJECTIVE:

Nitric oxide produced by endothelial nitric oxide synthase (eNOS) possesses multiple anti-atherosclerotic properties. Hence, enhanced expression of eNOS and increased Nitric oxide levels may protect against the development of atherosclerosis. Piper sarmentosum is a tropical plant with antioxidant and anti-inflammatory activities. This study aimed to investigate the effects of Piper sarmentosum on the eNOS and Nitric oxide pathway in cultured human umbilical vein endothelial cells (HUVECs).

METHODS:

HUVECs were divided into four groups: control, treatment with 180 μM hydrogen peroxide (H₂O₂), treatment with 150 μg/mL aqueous extract of Piper sarmentosum, and concomitant treatment with aqueous extract of PS and H₂O₂ for 24 hours. Subsequently, HUVECs were harvested and eNOS mRNA expression was determined using qPCR. The eNOS protein level was measured using ELISA, and the eNOS activity and Nitric oxide level were determined by the Griess reaction.

RESULTS:

Human umbilical vein endothelial cells treated with aqueous extract of Piper sarmentosum showed a marked induction of Nitric oxide. Treatment with PS also resulted in increased eNOS mRNA expression, eNOS protein level and eNOS activity in HUVECs.

CONCLUSION:

Aqueous extract of Piper sarmentosum may improve endothelial function by promoting NO production in HUVECs.     

脑室内注射BDNF抗体对大鼠海马NOS表达的影响

探讨脑室内注射脑源性神经营养因子 (BDNF)抗体阻断内源性BDNF对大鼠海马一氧化氮合酶 (NOS)阳性神经元的影响。脑室内注射BDNF抗体一周后 ,采用Morris水迷宫进行行为检测 ;并用NADPH 黄递酶组化染色方法观察海马NOS阳性神经元数目的变化。与对照组相比 ,实验组大鼠空间学习和记忆能力明显下降 (P <0 0 1) ;实验组大鼠海马CA1区NOS阳性神经元数目 (38 37± 5 2 3)明显少于对照组 (4 9 5 3± 5 74 ) (P <0 0 1) ;实验组DG区NOS阳性神经元数目 (4 8 77± 5 5 1)明显少于对照组 (6 0 4 0± 7 39) (P <0 0 1)。脑室内注射BDNF抗体可导致大鼠空间学习记忆能力下降 ,海马NOS阳性神经元数目减少 ,提示BDNF对学习和记忆的影响可能与海马NOS阳性神经元数目的变化有关     

氧化应激与糖尿病心血管并发症

心血管并发症如冠状动脉粥样硬化、心肌梗死和中风等是糖尿病患者致残和致死的主要原因之一。动物模型和临床研究均显示氧化应激加速了糖尿病心血管并发症的发生发展过程。活性氧可以通过多种机制产生,糖尿病患者的糖代谢和脂代谢紊乱能诱发活性氧的生成增多,引起氧化应激,最终导致糖尿病心血管并发症的发生。