Anions nitric oxide

OXYGEN, OXIDES 0X0 ANIONS NITRIC OXIDE SYNTHASE AUTOINHIBITION Nitrile aminohydrolase,... 

Fig. 2. Interplay among superoxide anion, nitric oxide, and eicosanoids in high oxidative stress. The biological function of nitric oxide in target cells is influenced by the cellular redox state. In increased oxidative stress, which results in an oxidizing environment, NO readily form free radicals, including the highly reactive peroxynitrite (OONO ). Peroxynitrite can influence eicosanoid synthesis by interfering with different enzyme systems of the arachidonic acid cascade. Increased free radicals may also catalyze nonenzymic peroxidation of membrane PUFA (e.g., arachidonic acid), resulting in increased production of isoprostanes that possess potent vasoconstrictor activity. PLA, phospholipase NO, nitric oxide NOS, nitric oxide synthase NADPH oxidase, vascular NAD(P)H oxidase 02 , superoxide anion PUFA, polyunsaturated fatty acids EPA, eicosapentaenoic acid DHA, docosahexaenoic acid COX, cyclooxygenase PGI2 synthase, prostacyclin synthase.

Clancy, R.M., Leszczynska-Piziak, J. and Abramason, S.B. (1992). Nitric oxide inhibits neutrophil superoxide anion production via a direct action on the NADPH oxidase. J. Clin. Invest. 90, 1116-1121. 

Wilson, K.T., Xie, Y., Musch, M.W. and Chang, E.B. (1992). Nitric oxide stimulates anion secretion and inhibits NaCl absorption in rat colon. Gastroenterology 102, A253. 

Beckman, J.S., Beckman, T.W., Chen, J., Marshall, P.A. and Freeman, B.A. (1990). Apparent hydroxyl radical formation by peroxynitrite implications for endothelial cell injury from nitric oxide and superoxide anion. Proc. Natl Acad. Sci. USA 87, 1620-1624. 

Research has shown that when polychlorpinen, ammonium nitrate, and superphosphate are present together in the soil, phosgene, carbon monoxide, nitric oxide, hydrochloric acid, ammonia, hydrocyanic anions, ozone, hydrogen fluoride and phosphide, etc. could appear in the air over the beet fields. Photooxidants could also appear. Airborne toxic compounds over this crop were noted in areas after precipitation with little wind, and with an air temperature of over 2CP . The combined and complex activity of pesticides and other chemical compounds led people who manually sowed beets to develop symptoms of poisoning. [21]... 

Results of a more recent series of investigations suggest that lead may cause hypertension in rats by increasing reactive oxygen species, which act as vasoconstrictors, and decreasing nitric oxide, a vasodilator released by the endothelium. The reactive oxygen species may be the hydroxyl radical, and did not appear to be the superoxide anion (Ding et al. 1998). 

K.Z. Kedziora-Kornatowska, M. Luciak, J. Blaszczyk, and W. Pawlak, Effect of aminoguanidine on the generation of superoxide anion and nitric oxide by peripheral blood granulocytes of rats with strep-tozotocin-induced diabetes. Clin. Chim. Acta 278, 45-53 (1998). 

C. Privat, S. Trevin, F. Bedioui, and J. Devynck, Direct electrochemical characterization of superoxide anion production and its reactivity toward nitric oxide in solution. J. Electroanal. Chem. 436, 261—265 (1997). 

Productive bimolecular reactions of the ion radicals in the contact ion pair can effectively compete with the back electron transfer if either the cation radical or the anion radical undergoes a rapid reaction with an additive that is present during electron-transfer activation. For example, the [D, A] complex of an arene donor with nitrosonium cation exists in the equilibrium with a low steady-state concentration of the radical pair, which persists indefinitely. However, the introduction of oxygen rapidly oxidizes even small amounts of nitric oxide to compete with back electron transfer and thus successfully effects aromatic nitration80 (Scheme 16). 

At present, new developments challenge previous ideas concerning the role of nitric oxide in oxidative processes. The capacity of nitric oxide to oxidize substrates by a one-electron transfer mechanism was supported by the suggestion that its reduction potential is positive and relatively high. However, recent determinations based on the combination of quantum mechanical calculations, cyclic voltammetry, and chemical experiments suggest that °(NO/ NO-) = —0.8 0.2 V [56]. This new value of the NO reduction potential apparently denies the possibility for NO to react as a one-electron oxidant with biomolecules. However, it should be noted that such reactions are described in several studies. Thus, Sharpe and Cooper [57] showed that nitric oxide oxidized ferrocytochrome c to ferricytochrome c to form nitroxyl anion. These authors also proposed that the nitroxyl anion formed subsequently reacted with dioxygen, yielding peroxynitrite. If it is true, then Reactions (24) and (25) may represent a new pathway of peroxynitrite formation in mitochondria without the participation of superoxide. 

Furthermore, Laranjinha and Cadenas [58] have recently showed that nitric oxide oxidizes 3,4-dihydroxyphenylacetic acid (DOPAC) to form nitrosyl anion and the DOPAC semiqui-none supposedly by one-electron transfer mechanism. 

In contrast to nitric oxide, which is firmly identified in biological systems and for which numerous (but not all) functions are known, the participation of other nitrogen species in biological processes is still hypothetical. At present, the most interest is drawn to the very reactive nitroxyl anion NOT It has been shown that nitroxyl (or its conjugate acid, HNO)... 

Pineda-Zavela, A.P. et al., Nitric oxide and superoxide anion production in monocytes from children exposed to arsenic and lead in region Lagunera, Mexico, Toxicol. Appl. Pharmacol. 198, 283, 2004. 

The diazeniumdiolate anions react with electrophiles to produce stable covalent compounds (Fig. 3.9) [213, 216]. These compounds have the ability to act as prodrugs, releasing nitric oxide only when metabolically or enzymatically converted to the diazeniumdiolate anion [217-219]. Several compounds ofthis class have been synthesized by reaction of alkyl or aryl halides, sulfate esters, epoxides, etc. with the ionic diazeniumdiolates [220, 221]. 

N. K., Palmer, R. M., Whittle, B. J., Moncada, S., Synthesis of nitric oxide from L-arginine by neutrophils. Release and interaction with superoxide anion, Biochem. J. 261 (1989), p. 293-296... 

Macrophages from endrin-exposed rats or mice showed an increase in the concentration of nitric oxide (Akubue and Stohs 1992 Bagchi et al. 1993d) and increased chemiluminescence and production of superoxide anion (Bagchi et al. 1993a). Based on these results and those described above for hepatic... 

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