Apocynin improves endothelial function and prevents the development of hypertension in fructose fed rat

Background and Objectives:

Exaggerated production of superoxide and inactivation of nitric oxide have been implicated in pathogenesis of hypertension. NAD(P)H oxidase is one of the major source of reactive oxygen species in vasculature. In the present study, we aimed to determine the effect of chronic administration of Apocynin an NAD(P)H oxidase inhibitor on endothelial function and hypertension in fructose-fed rat.

Materials and Methods:

Endothelial function, vascular superoxide, and nitric oxide production/bioavailability in aortas from fructose-fed rats and age-matched controls treated with or without apocynin were assessed using isometric tension studies in organ chambers. Systolic blood pressure was measured by the tail cuff method.

Results:

In fructose-fed rats, acetylcholine-induced relaxation was impaired, vascular superoxide production was increased, and nitric oxide bioavailability was decreased along with an increase in systolic blood pressure compared to controls. Apocynin treatment prevented the increased generation of superoxide, decreased nitric oxide bioavailability, impaired acetylcholine-induced relaxation, and elevation of systolic blood pressure.

Conclusion:

Chronic administration of apocynin improves the endothelial function by reducing oxidative stress, improving NO bioavailability, and prevents the development hypertension in fructose-fed rat.     

胡黄连素硝酮对大鼠急性肺损伤的保护作用及机制研究

目的探讨胡黄连素硝酮衍生物(AN-1)在保护叔丁基过氧化氢诱导的RAW 264.7细胞中的抗氧化作用及对脂多糖(LPS)诱导的大鼠急性肺损伤的保护作用。方法 MTT法测定AN-1对叔丁基过氧化氢(t-BHP)诱导的RAW264.7细胞损伤的保护作用。活性氧(ROS)敏感的荧光探针2',7'-二氢二氯荧光素(DCFH-DA,20μmol.L-1)标记细胞,激光共聚焦显微镜下观察活性氧强弱。Western blot法检测NADPH氧化酶亚基gp91phox表达。通过气管内滴注LPS建立大鼠急性肺损伤模型,胡黄连素(apocynin)及AN-1治疗两周,HE染色病理切片观察LPS诱导的急性肺损伤模型大鼠的肺组织切片,检测肺组织中总超氧化物岐化酶(SOD)活性变化。结果 AN-1在1和10μmol.L-1时可明显保护t-BHP诱导的细胞损伤,且在10μmol.L-1时作用效果最明显。AN-1呈剂量依赖性地减少t-BHP诱导RAW264.7细胞中ROS的产生,下调NADPH氧化酶亚基gp91phox的表达,病理切片显示AN-1给药两周对LPS诱导的大鼠急性肺损伤有明显的治疗作用并能提高肺组织中SOD的活性。结论胡黄连素硝酮衍生物通过下调NADPH氧化酶亚基gp91phox和清除细胞内ROS保护RAW 264.7细胞的氧化损伤,并且能明显改善LPS诱导的大鼠急性肺损伤,是治疗急性肺损伤潜在的药物。     

Effect of temperature-induced reactive oxygen species production on excitation-contraction coupling in mammalian skeletal muscle

1. Here we review evidence obtained recently by us indicating that the poor longevity of isolated mammalian skeletal muscle preparations at temperatures in the normal physiological range is related to the increased production of reactive oxygen species (ROS) in the resting muscle. 2. Temperature-induced ROS production increases markedly above 32 degrees C in isolated, resting skeletal muscle and is associated with the gradual and irreversible functional deterioration of the muscle. 3. The majority of the temperature-induced muscle ROS originates in the mitochondria and acts on various sites involved in excitation-contraction coupling.     

Chlamydia pneumoniae induces a pro-inflammatory phenotype in murine vascular smooth muscle cells independently of elevating reactive oxygen species

相似文献   

他巴唑对甲状腺细胞活性氧的影响

目的　观察他巴唑对甲状腺细胞活性氧 (ROS)的影响 ,探讨其作用的构效关系。方法　以 2′ ,7′二氯氢化荧光素和氢乙啡啶为细胞内H2 O2 与O- ·2 的荧光探针 ,以流式细胞术观察他巴唑及其结构类似物对甲状腺细胞活性氧的影响。结果　他巴唑对甲状腺细胞内外源性ROS均有清除作用 ,且这一作用呈剂量依赖性 ;无巯基的他巴唑结构类似物咪唑对ROS无清除作用 ,而谷胱甘肽过氧化物酶抑制物二乙马来酸可部分抑制他巴唑这种作用。结论　他巴唑对甲状腺细胞活性氧具清除效应 ,且这一效应可能与其分子中巯基有关     

微囊藻毒素-LR对小鼠巨噬细胞吞噬功能及活性氧水平的影响

目的观察微囊藻毒素LR(MC-LR)对原代和传代巨噬细胞功能的影响。方法取BALB/c小鼠腹腔巨噬细胞,体外培养液中分别加入终浓度为1,10,100和1000nmol.L-1的MC-LR,同时以巨噬细胞株RAW264.7为对照,分别采用中性红吞噬实验和二氢罗丹明123探针检测实验,测定细胞吞噬活性和细胞内活性氧(ROS)水平。结果MC-LR对小鼠腹腔巨噬细胞的吞噬功能有浓度依赖的抑制作用。当MC-LR浓度高于10nmol.L-1时,小鼠腹腔巨噬细胞的胞内ROS水平也明显降低。但MC-LR对小鼠巨噬细胞系RAW264.7细胞的吞噬功能和细胞内ROS水平均无明显影响。结论MC-LR可抑制小鼠腹腔巨噬细胞的吞噬功能和ROS水平,原代巨噬细胞对MC-LR的敏感性高于传代细胞RAW264.7。     

Nitric oxide and reactive oxygen species production causes progressive damage in rats after cessation of silica inhalation.

Our laboratory has previously reported results from a rat silica inhalation study which determined that, even after silica exposure ended, pulmonary inflammation and damage progressed with subsequent fibrosis development. In the present study, the relationship between silica exposure, nitric oxide (NO) and reactive oxygen species (ROS) production, and the resultant pulmonary damage is investigated in this model. Rats were exposed to silica (15 mg/m3, 6 h/day) for either 20, 40, or 60 days. A portion of the rats from each exposure were sacrificed at 0 days postexposure, while another portion was maintained without further exposure for 36 days to examine recovery or progression. The major findings of this study are: (1) silica-exposed rat lungs were in a state of oxidative stress, the severity of which increased during the postexposure period, (2) silica-exposed rats had significant increase in lung NO production which increased in magnitude during the postexposure period, and (3) the presence of silica particle(s) in an alveolar macrophage (AM) was highly associated with inducible nitric oxide synthase (iNOS) protein. These data indicate that, even after silica exposure has ended, and despite declining silica lung burden, silica-induced pulmonary NO and ROS production increases, thus producing a more severe oxidative stress. A quantitative association between silica and expression of iNOS protein in AMs was also determined, which adds to our previous observation that iNOS and NO-mediated damage are associated anatomically with silica-induced pathological lesions. Future studies will be needed to determine whether the progressive oxidative stress, and iNOS activation and NO production, is a direct result of silica lung burden or a consequence of silica-induced biochemical mediators.     

白藜芦醇诱导K562细胞凋亡过程中活性氧水平的改变

目的：探讨白藜芦醇对K562细胞的凋亡诱导效应和对K562细胞内活性氧水平的影响。方法：应用噻唑蓝(MTr)比色法、光镜、DNA琼脂糖凝胶电泳和流式细胞术(FCM)检测细胞凋亡；FCM测定细胞内活性氧(ROS)水平。结果：白藜芦醇显著抑制K562细胞增殖，并呈现典型的凋亡形态学改变；DNA电泳可见梯状条带出现；FCM分析显示S期细胞数明显增多，出现S／G，期阻滞，ROS水平升高。结论：白藜芦醇诱导K562细胞凋亡与细胞内活性氧水平升高有关。     

Effects of acetaminophen on reactive oxygen species and nitric oxide redox signaling in kidney of arsenic-exposed rats

We examined whether acetaminophen could alter renal oxidative stress induced by arsenic; also whether withdrawal of acetaminophen treatment can increase susceptibility of kidney to arsenic toxicity. Acetaminophen (400 and 1600 mg/kg) was co-administered orally to rats for 3 days after preexposure to arsenic (25 ppm) for 28 days (Phase-I) and thereafter, acetaminophen was withdrawn, but arsenic exposure was continued for another 28 days (Phase-II). Acetaminophen enhanced arsenic-induced lipid peroxidation, GSH depletion and ROS production and further decreased superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase activities. Increased peroxidation did not alter kidney weight, but increased serum urea nitrogen and creatinine. Arsenic did not alter basal, iNOS-mediated NO production or iNOS expression. Arsenic decreased cNOS-mediated NO release and eNOS expression in Phase-II. Acetaminophen increased their expressions and NO production in Phase-I. In Phase-II, arsenic-mediated effects on NO remained mostly unaffected with acetaminophen. Results reveal that acetaminophen enhanced the risk of arsenic-mediated oxidative stress in kidney. Discontinuation of acetaminophen administration also increased the susceptibility of kidney to nephrotoxic effect of arsenic. It appeared ROS were primarily responsible for oxidative stress in both the phases. NO may have a minor role in Phase-I, but does not contribute to redox signaling mechanism in Phase-II.     

Nicotine- and tar-free cigarette smoke induces cell damage through reactive oxygen species newly generated by PKC-dependent activation of NADPH oxidase

We examined cytotoxic effects of nicotine/tar-free cigarette smoke extract (CSE) on C6 glioma cells. The CSE induced plasma membrane damage (determined by lactate dehydrogenase leakage and propidium iodide uptake) and cell apoptosis {determined by MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] reduction activity and DNA fragmentation}. The cytotoxic activity decayed with a half-life of approximately 2 h at 37°C, and it was abolished by N-acetyl-l-cysteine and reduced glutathione. The membrane damage was prevented by catalase and edaravone (a scavenger of ^?OH) but not by superoxide dismutase, indicating involvement of ^?OH. In contrast, the CSE-induced cell apoptosis was resistant to edaravone and induced by authentic H₂O₂ or O₂^? generated by the xanthine/xanthine oxidase system, indicating involvement of H₂O₂ or O₂^? in cell apoptosis. Diphenyleneiodonium [NADPH oxidase (NOX) inhibitor] and bisindolylmaleimide I [BIS I, protein kinase C (PKC) inhibitor] abolished membrane damage, whereas they partially inhibited apoptosis. These results demonstrate that 1) a stable component(s) in the CSE activates PKC, which stimulates NOX to generate reactive oxygen species (ROS), causing membrane damage and apoptosis; 2) different ROS are responsible for membrane damage and apoptosis; and 3) part of the apoptosis is caused by oxidants independently of PKC and NOX.[Supplementary methods and Figure: available only at http://dx.doi.org/10.1254/jphs.11166FP]     

Reactive oxygen species and the central nervous system in salt-sensitive hypertension: possible relationship with obesity-induced hypertension

1. There are multiple and complex mechanisms of salt-induced hypertension; however, central sympathoexcitation plays an important role. In addition, the production of reactive oxygen species (ROS) is increased in salt-sensitive hypertensive humans and animals. Thus, we hypothesized that brain ROS overproduction may increase blood pressure (BP) by central sympathostimulation. 2. Recently, we demonstrated that ROS levels were elevated in the hypothalamus of salt-sensitive hypertensive animals. Moreover, intracerebroventricular anti-oxidants suppressed BP and renal sympathetic nerve activity more in salt-sensitive than non-salt-sensitive hypertensive rats. Thus, brain ROS overproduction increased BP through central sympathoexcitation in salt-sensitive hypertension. 3. Salt sensitivity of BP is enhanced in obesity and metabolic syndrome. Interestingly, it is also suggested that, in obesity-induced hypertension models, increases in BP are caused by brain ROS-induced central sympathoexcitation. 4. Recent studies suggest that increased ROS production in the brain and central sympathoexcitation may share a common pathway that increases BP in both salt- and obesity-induced hypertension.     

Contributions of reactive oxygen species and mitogen-activated protein kinase signaling in arsenite-stimulated hemeoxygenase-1 production

Hemeoxygenase-1 (HO-1) is an oxidative stress responsive gene upregulated by various physiological and exogenous stimuli. HO-1 has cytoprotective activities and arsenite is a potent inducer of HO-1 in many cell types and tissues, including epidermal keratinocytes. We investigated the potential contributions of reactive oxygen species (ROS) generation and mitogen-activated protein kinase (MAPK) activation to arsenite-dependent regulation of HO-1 in HaCaT cells, an immortalized human keratinocyte line. Both epidermal growth factor (EGF) and arsenite stimulated ROS production was detected by dihydroethidium (DHE) staining and fluorescence microscopy. Arsenite induced HO-1 in a time- and concentration-dependent manner, while HO-1 expression in response to EGF was modest and evident at extended time points (48-72 h). Inhibition of EGF receptor, MEK I/II or Src decreased arsenite-stimulated HO-1 expression by 20-30%. In contrast, addition of a superoxide scavenger or inhibition of p38 activity decreased the arsenite-dependent response by 80-90% suggesting that ROS and p38 are required for HO-1 induction. However, ROS generation alone was insufficient for the observed arsenite-dependent response as use of a xanthine/xanthine oxidase system to generate ROS did not produce an equivalent upregulation of HO-1. Cooperation between ERK signaling and ROS generation was demonstrated by synergistic induction of HO-1 in cells co-treated with EGF and xanthine/xanthine oxidase resulting in a response nearly equivalent to that observed with arsenite. These findings suggest that the ERK/MAPK activation is necessary but not sufficient for optimal arsenite-stimulated HO-1 induction. The robust and persistent upregulation of HO-1 may have a role in cellular adaptation to chronic arsenic exposure.     

六价铬对肝细胞内活性氧和腺苷酸转运体1转录水平的影响

目的探讨重金属六价铬[Cr(Ⅵ)]的体外肝毒性。方法 L-02肝细胞经Cr(Ⅵ)0,2,4,8,16和32μmol.L-1分别染毒12,24或36 h后,采用逆转录-荧光定量聚合酶链反应(RT-qPCR)和荧光光度法分别对腺苷酸转运体1(ANT1)mRNA表达水平和活性氧簇(ROS)水平进行检测。结果 Cr(Ⅵ)32μmol.L-1处理细胞12和24 h后,ROS水平明显升高,而处理36 h后,ROS水平明显下降。Cr(Ⅵ)2～32μmol.L-1处理细胞12和24 h后,细胞内ANT1 mRNA呈明显低表达水平,而处理36 h后,细胞内ANT1 mRNA表达水平明显增高,达正常对照组的2倍左右。结论 Cr(Ⅵ)在早期(12,24 h)可使L-02肝细胞内ROS水平升高,发生氧化应激,在后期(36 h)可诱导ANT1 mRNA表达水平升高,发生能量代谢应激,可能是Cr(Ⅵ)诱导细胞线粒体损伤的分子毒性机制之一。     

白藜芦醇对急性脊髓损伤早期脂质过氧化反应和活性氧水平的抑制作用

目的 :探讨脊髓损伤后使用白藜芦醇 (resvera trol,Res)对脊髓损伤 (SCI)早期脂质过氧化反应和活性氧水平的抑制作用。方法 :采用重物下落撞击法制备成年大鼠的SCI模型 ,于损伤后即刻腹腔注射给予Res 5 0 ,1 0 0mg·kg-1和甲基强的松龙 (MPSS)1 0 0mg·kg-1,测定SCI后 1 ,2 4,48h时Res组受损脊髓组织超氧化物歧化酶 (SOD)和脂质过氧化反应产物丙二醛 (MDA)及活性氧 (ROS)水平 ,并与MPSS组进行疗效对比。结果 :Res 5 0mg·kg-1与 1 0 0mg·kg-1均能够显著提高SCI后损伤部位SOD水平和抑制MDA产生 (P <0 .0 1 ) ,以 48h为最明显 ;显著降低ROS水平 (P <0 .0 1 ) ,也以 48h最大 ,抑制率大于40 % ;且有明显剂量依赖性 ,作用与MPSS相当或更优。结论 :Res可以有效抑制脊髓损伤后早期受损局部脂质过氧化反应和活性氧水平 ,对脊髓损伤有潜在的保护与治疗作用     

Placental mitochondria and reactive oxygen species in the physiology and pathophysiology of pregnancy

Mitochondria are central to cell function. The placenta forms the interface between maternal and fetal systems, and placental mitochondria have critical roles in maintaining pregnancy. The placenta is unusual in having two adjacent cell layers (cytotrophoblasts and the syncytiotrophoblast) with vastly different mitochondria that have distinct functions in health and disease. Mitochondria both produce the majority of reactive oxygen species (ROS), and are sensitive to ROS. ROS are important in allowing cells to sense their environment through mitochondrial-centred signalling, and this signalling also helps cells/tissues adapt to changing environments. However, excessive ROS are damaging, and increased ROS levels are associated with pregnancy complications, including the important disorders preeclampsia and gestational diabetes mellitus. Here we review the function of placental mitochondria in healthy pregnancy, and also in pregnancy complications. Placental mitochondria are critical to cell function, and mitochondrial damage is a feature of pregnancy complications. However, the responsiveness of mitochondria to ROS signalling may be central to placental adaptations that mitigate damage, and placental mitochondria are an attractive target for the development of therapeutics to improve pregnancy outcomes.