Oxygen reactive species

C 2 anion superoxide —H2O2 hydrogen peroxide OH hydroxyl radical 

Reactive oxygen species can attack all cell compartments, lipids, proteins, and DNA. The cell will activate enzymatic systems to limit the generation of reactive oxygen species. Also, 

Substitutions or mutations in phosphorylatable sites, such as serine residues, can have opposite affects. For example, substitution of Ser129 with Gly129 in CYP2E1 has been reported to increase the catalytic activity following phosphorylation by PKA. 

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One of the important consequences of neuronal stimulation is increased neuronal aerobic metabolism which produces reactive oxygen species (ROS). ROS can oxidize several biomoiecules (carbohydrates, DNA, lipids, and proteins). Thus, even oxygen, which is essential for aerobic life, may be potentially toxic to cells. Addition of one electron to molecular oxygen (O,) generates a free radical [O2)) the superoxide anion. This is converted through activation of an enzyme, superoxide dismurase, to hydrogen peroxide (H-iO,), which is, in turn, the source of the hydroxyl radical (OH). Usually catalase... 

Halliwell, B. (1992). Reactive oxygen species and the central nervous system. /. Neurochem. 59, 1609-1623. 

Anthracyclins. Figure 2 Mechanisms of anthracycline-induced apoptosis of tumor cells. ROS, reactive oxygen species topo II, topoisomerase II cyt c, cytochrome c. 

EPI, epimbicin DOX, doxorubicin ROS, reactive oxygen species DNR, daunorubicin... 

LTB4, PAF, IL-1, IL-8, reactive oxygen species, lysosomal enzymes... 

P450 Mono-oxygenase System Reactive Oxygene Species Oxidative Stress Vitamin C Vitamin E... 

Airway inflammation is a characteristic clinical feature of asthma. The distinction between the LAR and chronic inflammation becomes more difficult as the disease progresses. Infiltrated leukocytes release ototoxic mediators such as reactive oxygen species (ROS) and cationic (basic) proteins causing epithelial damage and cyfo/cmas that perpetuate the inflammation. Sustained inflammation leads to airway hyperrespon-siveness and airway remodeling. 

Bronchial Asthma. Figure 2 Mechanisms of bronchial hyperresponsiveness. Toxic products from eosinophils [cationic peptides, reactive oxygen species (ROS)] cause epithelial injury. Nerve endings become easily accessible to mediators from mast cells, eosinophils [eosinophil-derived neurotoxin (EDN)], and neutrophils, and to airborne toxicants such as S02. Activation of nerve endings stimulates effector cells like mucosal glands and airway smooth muscle either directly or by cholinergic reflexes. 

ROS, reactive oxygen species AHR, airway hyperresponsiveness MMP, matrix metalloprotease. Correlates with cough and chronic bronchitis. bNumber increases with disease severity. 

Increased accumulation of reactive oxygen species (ROS) in biological systems. 

Reactive Oxygen Species Antioxidants Oxidative Stress... 

In the interstitium, angiotensin II induces proliferation of mesangial cells and fibroblasts and the synthesis of collagen and other matrix molecules by these cells via the ATI receptor. Moreover, by the concomitant stimulation of chemoattractant cytokines, inflammation is induced. These processes are mediated by endothelin, transforming growth factor(3, and reactive oxygen species, and finally lead to interstitial fibrosis and glomerulosclerosis observed in hypertension and diabetes. 

Azelaic acid is effective on P. acnes suppression, even if less than benzoyl peroxide. The anti-inflammatory effect of azelaic acid seems to be related to a decreased production of reactive oxygen species by neutrophils. Azelaic acid may also regulate the ductal cell keratinization, reducing the number of comedones, ft is not sebosuppressive. 

Suzuki S, Miyachi Y, Niwa Y, Isshiki N (1989) Significance of reactive oxygen species in distal flap necrosis and its salvage with liposomal SOD. Br J Plast Surg 42 559-564... 

NF-kB Activators Proinflammatory cytokines Bacterial and viral infection Reactive oxygen species... 

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