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Introduction to Oxidative (Eu)stress in Exercise Physiology
Published in James N. Cobley, Gareth W. Davison, Oxidative Eustress in Exercise Physiology, 2022
Gareth W. Davison, James N. Cobley
Nitric oxide [nitrogen monoxide] is by definition a free radical due to the presence of a single unpaired electron (Sen et al., 2000). is produced in several mammalian cells and can control blood flow, thrombosis and neural activity (Beckman and Koppenol, 1996). It has the ability to rapidly diffuse between cells and bind to to produce the peroxynitrite anion (ONOO−), which although not a free radical has the potential to attack and damage cellular membranes (Sen et al., 2000). One-electron reduction of NO would yield the nitroxyl anion, which is a relatively unreactive and short-lived species (Halliwell and Gutteridge, 2015).
Excitotoxicity and Nitric Oxide
Published in Richard A. Jonas, Jane W. Newburger, Joseph J. Volpe, John W. Kirklin, Brain Injury and Pediatric Cardiac Surgery, 2019
It turns out that NO, which we generally call nitrogen monoxide, is just like ice cream that comes in several flavors, because the properties of NO depend on how many electrons it has. Physiologically there is indeed nitric oxide, which is NO·, but if you take away one electron, the resulting substance is called nitrosonium ion, or NO+. In fact, all nitroso-compounds have nitrosonium ion or an equivalent in them. They do not have nitric oxide.
Procedures for Writing Formulas and Naming Compounds
Published in Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk, Survival Guide to General Chemistry, 2019
Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk
NO Nitrogen( )nitrogen ( )oxideN1 = nitrogen; note that if the first element in the name has the number “1,” the prefix mono is dropped O1 = monoxide; the prefix mono (with the last “o” dropped) is required for the second element in the formula. Name: nitrogen monoxide
Hijacking of immune defences by biofilms: a multifront strategy
Published in Biofouling, 2019
Davide Campoccia, Rasoul Mirzaei, Lucio Montanaro, Carla Renata Arciola
The functions of ROS as bactericidal factors clearly emerge in chronic granulomatous disease, a genetic condition where the formation of ROS is impaired. Affected patients suffer from recurrent bacterial infections and depend on antibiotics for a lifetime treatment, as causal drugs are not available (Notarangelo et al. 2004; Lekstrom-Himes and Gallin 2000). The mechanisms for the generation of ROS rely on three distinct enzymes: NADPH oxidase, myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS). The latter mechanism is involved in the production of the bactericidal nitrogen monoxide (NO) and, more generally, of reactive nitrogen species (RNS). Given the critical importance of ROS production in the defence from infections, the existence of compensatory mechanisms in the case of some dysfunction of other paths is of critical importance. In this regard, iNOS has emerged to compensate for the lack of MPO (Brovkovych et al. 2008).
Pharmaceuticals agents for preventing NSAID-induced gastric ulcers: a patent review
Published in Expert Review of Clinical Pharmacology, 2021
Daiane Franco Teixeira, Anamaria Mendonça Santos, Ana Maria Santos Oliveira, José Adão Carvalho Nascimento Júnior, Luiza Abrahão Frank, Marilia Trindade De Santana Souza, Enilton Aparecido Camargo, Mairim Russo Serafini
A nitric oxide donor molecule are compounds that have a region that contains nitric oxide, which is available to be directly released or chemically transferred nitrogen monoxide (nitric oxide), preferably in its positively charged nitroson form, to another molecule [17].
Mechanistic role of epigallocatechin-3-gallate in regulation of the antioxidant markers in ethanol induced liver damage in mice
Published in Alexandria Journal of Medicine, 2022
Mujinya Pastori, Stellamaris Kembabazi, Wandera Allan, Robert Siida, Mpumbya Jackie Rachael, Solomon Adomi Mbina, Daniel Okumu, Dominic Terkimbi Swase, Kimanje Kyobe Ronald, Kwizera Eliah, Niwamanya Boaz, Ondari Erick Nyakundi
Under physiological conditions SOD and CAT are endogenous antioxidant enzymes that eliminate ROS, thus preventing oxidative damage of cellular biomolecules. However, the activity of these enzymes has been shown to decrease due to prolonged exposure to oxidative stress [16]. The findings herein indicated a significant decrease in activities of both SOD and CAT in mice that consumed alcohol compared to the control group and are in agreement [3] who also reported a decrease in activities of the same enzymes after exposing rodents to ethanol. It is possible that over-production of superoxide radicals from chronic consumption and metabolism of ethanol reacted with nitrogen monoxide ion to form peroxynitrite that nitrated SOD leading to decrease in the activity of SOD compared to control [17]. SOD activity is also regulated by either induction or repression [18] and Kaep1/Nrf2/ARE signaling pathway, majorly involved in regulation of antioxidant enzymes [19]. It has been reported that polyphenols including EGCG could modulate Kaep1/Nrf2/ARE signaling pathway leading to increased SOD-2 expression to prevent oxidative stress induced by ethanol [20]. Therefore, EGCG increased activity of SOD by increasing SOD-2 gene expression. Whereas CAT activity is regulated by either induction or repression, this study showed that chronic consumption of ethanol by mice did not affect expression of CAT expression yet the enzyme activity significantly decreased compared to the control group, depicting that CAT activity is not regulated by either induction or repression during ethanol induced oxidative stress. Studies show that phosphorylation of CAT is a post-translational modification mechanism regulating CAT activity and it is dependent on ROS levels. It is evident that chronic consumption of ethanol resulted into production of uncontrolled levels of ROS, which could have led to dissociation of the c-Abl and Arg from phosphorylated CAT and the enzyme undergoes ubiquitination and proteasomal degradation resulting into decreased CAT activity [21]. Additionally, reports show that activity of CAT is decreased during prolonged oxidative stress through dephosphorylation of CAT enzyme by phosphatases [22]. Daily EGCG administration one hour before consumption of ethanol for 35 days also did not affect the expression of CAT yet the CAT activity increased. This could be due to effect of EGCG preventing ROS elevation, and in turn low levels of ROS stimulated phosphorylation of CAT by c-Abl and Arg tyrosine kinases resulting into increased CAT activity [23].