Xanthine Oxidase (Xanthine Dehydrogenase)

Fried, Rainer; Fried, Lygia W.

doi:10.1016/b978-0-12-091302-2.50027-x

Cited by 51 publications

(38 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The use of the varied cutting patterns obtained from restriction enzymes should help define the cloned polyoma defective DNA molecules (1). Also, the restriction enzymes can be used to try and assign genetic markers to the physical map in order to create a genetic map, as has been achieved with OX174 (13).…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Polyma DNA: A Physical Map

Griffin

Fried

Cowie

1974

Proc. Natl. Acad. Sci. U.S.A.

178

137

View full text Add to dashboard Cite

The action of restriction enzymes on (2). Supercoiled viral DNA was purified from the supernatant by phenol extraction, dialysis against 1 M NaCl (pH 7.5), and ethanol precipitation, followed by equilibrium centrifugation in CsCl/ethidium bromide (3). Supercoiled viral DNA was further purified by neutral sucrose density gradient centrifugation (1). Yields of purified product varied from 1 to 5 Mg per 90-mm dish, with specific activity about 4 X 105 cpm/,ug.Enzymes. All the restriction enzymes used, except Hpaii

show abstract

Section: Methodsmentioning

confidence: 99%

“…All virus preparations were derived from a single plaque (A-2) of the large-plaque strain and were grown up at low multiplicity, as described (1).…”

Section: Methodsmentioning

confidence: 99%

Polyma DNA: A Physical Map

Griffin

Fried

Cowie

1974

Proc. Natl. Acad. Sci. U.S.A.

178

137

View full text Add to dashboard Cite

show abstract

“…The resultant supernatant fractions were analyzed to estimate the activity of each enzyme. Xanthine oxidase activity was estimated according to the method of Fried & Fried (1974). Superoxide dismutase activity was calculated from the inhibited reduction of nitro blue tetrazolium according to the method of Beauchamp & Fridovich (1971).…”

Section: Estimation Of Lipid Peroxide and Non-protein Sulfhydryl In Lmentioning

confidence: 99%

Effect of Nitric Oxide Synthase Inhibitors on Lipid Peroxide Formation in Liver Caused by Endotoxin Challenge

Sakaguchi

Furusawa

Yokota

et al. 2000

Pharmacology & Toxicology

View full text Add to dashboard Cite

This study investigated the effect of nitric oxide on lipid peroxide formation during endotoxaemia. Nitric oxide synthase inhibitors N G -monomethyl-L-arginine acetate (L-NMMA, 20 mg/kg, intravenously), N G -nitro-L-arginine-methyl ester (L-NAME, 10 mg/kg, intravenously), and N G -nitro-L-arginine (L-NA, 10 mg/kg, intravenously), and a relatively selective inducible nitric oxide synthase inhibitor aminoguanidine (10 mg/kg, intravenously), did not protect against endotoxin-induced death of mice. Superoxide dismutase activity in liver 18 hr after administration of endotoxin (6 mg/kg, intraperitoneally) to L-arginine analogues (L-NMMA, L-NAME, L-NA)-treated mice was lower than in mice treated with endotoxin alone, whereas the administration of L-arginine analogues increased xanthine oxidase activity in the livers of endotoxin-injected mice compared with mice treated with endotoxin alone. In mice treated with L-arginine analogues and aminoguanidine, the levels of non-protein sulfhydryl and lipid peroxide in liver 18 hr after endotoxin injection did not show significant differences from mice treated with endotoxin alone. L-Arginine analogues and aminoguanidine had little effect on lipid peroxide formation in liver caused by endotoxin. Treatment with aminoguanidine (300 mM) significantly inhibited endotoxin-induced intracellular peroxide in J774A.1 cells, however, aminoguanidine did not affect endotoxininduced cytotoxicity in J774A.1 cells. Our results clearly demonstrate that treatment with catalase (10 mg/ml), D-mannitol (10 mM), or superoxide dismutase (100 U/ml), has little or no effect on nitric oxide production by endotoxin (1 mg/ml)-activated J774A.1 cells. These findings suggest that nitric oxide is not crucial for lipid peroxide formation during endotoxaemia. Therefore, it is unlikely that nitric oxide plays a significant role in liver injury caused by free radical generation in endotoxaemia.

show abstract

“…xanthine oxidoreductase, XOR) that convert adenine or guanine to hypoxanthine or xanthine, and xanthine to uric acid by deamination (Fig. 1, Fried & Fried 1974). XOR is a flavoprotein that needs no cytochrome to mediate between it and oxygen; the product of the reaction is H 2 O 2 , but since all cells contain catalase, the eventual outcome is that the substance is oxidated to product and H 2 O (Harrison 1959).…”

Section: Introductionmentioning

confidence: 99%

Purineolytic capacity response of Nephrops norvegicus to prolonged emersion: an ammonia detoxification process

Bernasconi¹,

Uglow²

2011

Aquat. Biol.

View full text Add to dashboard Cite

Under prolonged (> 24 h) emersion, Norway lobster Nephrops norvegicus changed purineolytic pathways in response to increased levels of circulating ammonia. Haemolymph levels of urea and uric acid more than doubled during emersion, but xanthine oxidase was not detected, even after 72 h emersion. Xanthine dehydrogenase (XDH) was the only form of xanthine oxidoreductase detected, so the metabolic costs of producing uric acid would have been relatively small. Although ammonia, urea, uric acid and XDH all accumulated in the haemolymph during emersion, the relative proportions of ammonia and urea stayed the same at all times, which suggests the presence of enzymes from the uricolyic pathway (e.g. uricase and urease). Supranormal ammonia effluxes occurred almost immediately following re-immersion in amounts that indicate a high degree of hypoxia tolerance under emersion and that this is negatively related with the prevailing temperature. We conclude that N. norvegicus has purineolytic capacity and, under prolonged hypoxia, produces purines de novo as an ammonia-detoxification strategy that has probable survival value for a benthic burrowing species that may experience periods of severe hypoxia.

show abstract

Xanthine Oxidase (Xanthine Dehydrogenase)

Cited by 51 publications

References 28 publications

Polyma DNA: A Physical Map

Polyma DNA: A Physical Map

Effect of Nitric Oxide Synthase Inhibitors on Lipid Peroxide Formation in Liver Caused by Endotoxin Challenge

Purineolytic capacity response of Nephrops norvegicus to prolonged emersion: an ammonia detoxification process

Contact Info

Product

Resources

About