Search results for "ADP"

Determination of Plasma Lipid Hydroperoxides by an NADPH/NADP + Coupled Enzyme Reaction System. Evaluation of a Method

1998

Summary: Several techniques based on different principles have been proposed to measure lipid hydroperoxides. Enzymatic methods are sensitive and can be quite specific but they are subject to interference by inhibitors and not all are stoichiometric. The present work proposes some modifications of the Heath & Tappel (Anal Biochem 1976; 7:184—91) enzymatic method of determination of lipid hydroperoxides in order to standardize and automate it and to meet the analytical criteria required for a biological assay. The proposed new protocol and the automated assay give acceptable within-run and between-run precisions, with coefficients of variation of 3.34% and 5.80%, respectively, at the usual p…

Sildenafil protects human mammary epithelial cells against ROS production induced by estradiol

2010

Several studies suggest that xanthine dehydrogenase (XDH) and its oxidase form (XO) play an important role in various types of ischemic and vascular injuries. Recently, we have demonstrated that estradiol (E2) induces a significant decrease of the expression and activity of XDH and of its conversion to XO in human mammary epithelial cells. E2 is known to induce upregulation of eNOS gene expression in aortic endothelial cells. Because the XO-derived O2·- combines with ·NO to yield ONOO-, and considering that ONOO- converts XDH to XO, the resulting increase of XO activity and reactive oxygen species production would eventually lead to a further increase of ONOO- production, thus creating a vi…

Interplays between nitric oxide and reactive oxygen species in cryptogein signalling

2014

The cellular messenger nitric oxide (NO) has many functions in plants. In this study, we investigated its interplays with Reactive Oxygen Species (ROS) in the defense responses triggered by the elicitin cryptogein produced by the oomycete Phytophthora cryptogea. The production of NO induced by cryptogein in tobacco cell suspensions was partly regulated through a ROS-dependent pathway involving the NADPH oxidase NtRBOHD. In turn, NO down-regulated the level of H2O2 derived from NtRBOHD activity. Both NO and ROS synthesis appeared to be under the control of two redundant isoforms of histone deacetylases of type 2 acting as negative regulators of cell death. Occurrence of an interplay between …

2013

Re-canalization of cerebral vessels in ischemic stroke is pivotal to rescue dysfunctional brain areas that are exposed to moderate hypoxia within the penumbra from irreversible cell death. Goal of the present study was to evaluate the effect of moderate hypoxia followed by reoxygenation (MHR) on the evolution of reactive oxygen species (ROS) and blood-brain barrier (BBB) integrity in brain endothelial cells (BEC). BBB integrity was assessed in BEC in vitro and in microvessels of the guinea pig whole brain in situ preparation. Probes were exposed to MHR (2 hours 67-70 mmHg O2, 3 hours reoxygenation, BEC) or towards occlusion of the arteria cerebri media (MCAO) with or without subsequent repe…

Uncoupling of Endothelial Nitric Oxide Synthase in Cardiovascular Disease and its Pharmacological Reversal

2010

Publisher Summary This chapter discusses the role of oxidative stress in vascular dysfunction and atherogenesis, and strategies for its prevention. Endothelial dysfunction and oxidative stress have been identified as a common denominator of many cardiovascular risk factors. They support pro-inflammatory, prothrombotic, proliferative, and vasoconstrictor mechanisms that are involved in the initiation, progression, and complications of atherosclerosis. The pathophysiologic causes of oxidative stress involve changes in a number of different enzyme systems. Increased production of ROS by uncoupled eNOS is likely to contribute significantly to vascular oxidative stress and endothelial dysfunctio…

Metabolic cross-talk between pathways of terpenoid backbone biosynthesis in spike lavender

2015

Abstract The metabolic cross-talk between the mevalonate (MVA) and the methylerythritol phosphate (MEP) pathways in developing spike lavender ( Lavandula latifolia Med) was analyzed using specific inhibitors and on the basis of 13 C-labeling experiments. The presence of mevinolin (MEV), an inhibitor of the MVA pathway, at concentrations higher than 0.5 μM significantly reduced plant development, but not the synthesis of chlorophylls and carotenoids. On the other hand, fosmidomycin (FSM), an inhibitor of the MEP pathway, at concentrations higher than 20 μM blocked the synthesis of chlorophyll, carotenoids and essential oils, and significantly reduced stem development. Notably, 1.2 mM MVA cou…

Nitroglycerin-Induced Endothelial Dysfunction and Tolerance Involve Adverse Phosphorylation and S -Glutathionylation of Endothelial Nitric Oxide Synt…

2011

Objective— Continuous administration of nitroglycerin (GTN) causes tolerance and endothelial dysfunction by inducing reactive oxygen species (ROS) production from various enzymatic sources, such as mitochondria, NADPH oxidase, and an uncoupled endothelial nitric oxide synthase (eNOS). In the present study, we tested the effects of type 1 angiotensin (AT 1 )-receptor blockade with telmisartan on GTN-induced endothelial dysfunction in particular on eNOS phosphorylation and S -glutathionylation sites and the eNOS cofactor synthesizing enzyme GTP–cyclohydrolase I. Methods and Results— Wistar rats were treated with telmisartan (2.7 or 8 mg/kg per day PO for 10 days) and with GTN (50 mg/kg per d…

Saldus ievērojamākie kultūrvēsturiskie objekti

2019

Pētījuma temats ir “Saldus ievērojamākie kultūrvēsturiskie objekti”. Pētījuma galvenā problēma ir apkopotas informācijas trūkums par Saldus brīvprātīgo ugunsdzēsēju biedrību, Saldus Kalnsētas parku un Saldus Sv. Jāņa evaņģēliski luterisko baznīcu dažādās atmiņas informācijas institūcijās kā Saldus pilsētas bibliotēka, Jaņa Rozentāla Saldus vēstures un mākslas muzejs un citās iestādēs. Bakalaura darba mērķis ir izpētīt pētāmo objektu attīstību. Padziļinātāk izpētīt šo objektu veidošanās laiku, raksturojumu, apkārtnes raksturojumu, bijušos un tagadējos īpašniekus un svarīgākos notikumus. Pētījumā kā galvenās datu vākšanas metodes tika izmantotas dokumentu analīze un daļēji strukturēta intervi…

Valoración de las neuronas NADPH-d en la corteza visual : estudio experimental en rata Wístar

2013

Las células NADPH-diaforasa (nicotinamida adenin dinucleotido fosfatasa reducida), son células que están directamente relacionadas con la enzima óxido nítrico sintetasa (ONS), productora del óxido nítrico (ON) neuronal. Se ha podido comprobar que la NADPH-diaforasa y la ONS se han localizado en las mismas poblaciones neuronales y que su actividad es paralela a la producción de ON y GMPc. (1). De manera que, si localizamos las células NADPH-diaforasa positivas, podremos localizar indirectamente a aquéllas que producen el ON. En cuanto a su actividad enzimática, NADPH es una enzima del grupo de las deshidrogenasas, es decir, tienen la capacidad de captar el hidrógeno de una sustancia y transf…

Human Enterovirus Group B Viruses Rely on Vimentin Dynamics for Efficient Processing of Viral Nonstructural Proteins.

2019

A virus needs the host cell in order to replicate and produce new progeny viruses. For this, the virus takes over the host cell and modifies it to become a factory for viral proteins. Irrespective of the specific virus family, these proteins can be divided into structural and nonstructural proteins. Structural proteins are the building blocks for the new progeny virions, whereas the nonstructural proteins orchestrate the takeover of the host cell and its functions. Here, we have shown a mechanism that viruses exploit in order to regulate the host cell. We show that viral protein synthesis induces vimentin cages, which promote production of specific viral proteins that eventually control apo…