Search results for "Nitric Oxide"
showing 10 items of 1075 documents
Expression, regulation and function of carrier proteins for cationic amino acids.
2001
Different carrier proteins exhibiting distinct transport properties participate in cationic amino acid transport. There are sodium-independent systems, such as b+, y+, y+L and b0,+, and a sodium-dependent system B0,+, most of which have now been identified at the molecular level. In most non-epithelial cells, members of the cationic amino acid transporter (CAT) family mediating system y+ activity seem to be the major entry pathway for cationic amino acids. CAT proteins underlie complex regulation at the transcriptional, post-transcriptional and activity levels. Recent evidence indicates that individual CAT isoforms are necessary for providing the substrate for nitric oxide synthesis, for ex…
Expression and Expressional Control of Nitric Oxide Synthases in Various Cell Types
1995
Publisher Summary Nitric oxide (NO) can produce posttranslational modifications of proteins (via ADP ribosylation) and is capable of destroying parasites and tumor cells by inhibiting iron-containing enzymes or directly interacting with the DNA of these cells. In view of this multitude of functions of NO, it is important to understand how cells accomplish and regulate their NO production. Three isozymes of NOS have been identified, and their protein, cDNA, and genomic DNA structures have been elucidated. In humans NOS I, II, and III are encoded by three different genes, located on chromosomes 12, 17, and 7 respectively. The cDNAs for these enzymes have been isolated. All NOS isozymes oxidiz…
Identification and role of inflammatory oxygen free radicals in cardiac ischemia and reperfusion injury
2003
Prolonged myocardial ischemia results in a variety of severe cellular, metabolic and ultra-structural damages. It is therefore generally accepted that reperfusion is an absolute prerequisite for the survival of ischemic tissue. However, reperfusion may precipitate arrhythmias, cause myocardial stunning and accelerate necrotic process. Oxygen free radicals have been suggested as possible mediators of reperfusioninduced injury and there is circumstantial evidence that supports this hypothesis. Indirect evidence in support of this concept derives from studies in which antioxidant enzymes, enzyme inhibitors, free radical scavengers and iron chelators are able to protect against reperfusion inju…
Cavernolide
2000
Abstract The inhibitory effect of cavernolide, a novel C 21 terpene lactone isolated from the sponge Fasciospongia cavernosa , on PLA 2 and other enzyme activities involved in the inflammatory process was studied. Cavernolide inhibited human synovial sPLA 2 in a concentration-dependent manner with an IC 50 value of 8.8 μM. Besides, this compound decreased in the nanomolar range the myeloperoxidase degranulation process using different stimuli. Cavernolide also inhibited TNFα, NO and PGE 2 production in intact cell experiments. NO and PGE 2 reduction was the consequence of the inhibition on iNOS and COX-2 expression because it did not affect inducible nitric oxide synthase and cyclooxygenase…
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 …
The Role of Mitochondrial Reactive Oxygen Species Formation for Age-Induced Vascular Dysfunction
2010
Aging is an important risk factor for the development of cardiovascular diseases, which can be accelerated by atherosclerosis, diabetes, hypercholesterolemia, or obesity. Vascular aging is mainly characterized by endothelial dysfunction, an alteration of endothelium-dependent signaling processes, and vascular remodeling. The underlying mechanisms include increased production of reactive oxygen species (ROS), inactivation of nitric oxide (•NO), and subsequent formation of reactive nitrogen and oxygen species (RNOS). Elevated RNOS may exhibit new messenger functions by posttranslational oxidative modification of intracellular regulatory proteins or lead to irreversible alterations of biologic…
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…
Plant iNOS: conquest of the Holy Grail
2003
In animals, nitric oxide (NO) is produced by a family of enzymes named nitric oxide synthases (NOSs). Although no NOS-like gene has been found in the Arabidopsis thaliana genome, biochemical studies have suggested that a NOS-like protein is likely to be activated in plants resisting pathogens. This protein has been recently identified as a variant P protein of glycine decarboxylase. This discovery means that studies of nitric oxide signalling functions in plants are now entering a new phase.
Neuronal Nitric Oxide Synthase
2007
Neuronal nitric oxides synthase (nNOS; also referred to as NOS1 or NOS I) is a low-output enzyme that is primarily expressed in neurons. Like eNOS, it is a low-output NOS whose activity is regulated by Ca++ and calmodulin, and that produces NO in a pulsatile fashion. nNOS has a widespread distribution in the central and peripheral nervous systems. In addition, nNOS mRNA transcripts and/or protein have also been detected in non-neuronal cell types, such as rhabdomyocytes, epithelial cells, mast cells, and neutrophils …
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…