Xanthine oxidase is a member of molybdoenzyme family and has catalytic role in purine degradation, metabolizing hypoxanthine and xanthine to uric acid with the generation of superoxides. In the present study, microtitre plate based colorimetric assay was used to screen the xanthine oxidase producing microorganisms from the soil treated with hypoxanthine with different concentrations (2mM, 4mM, ...

The following evidence has led to the conclusion that xanthine oxidase, with its usual electron donors, is capable of reducing nicotinamide N-oxide to nicotinamide. 1. The purest enzyme fraction from hog liver which catalyzes the reduction has the spectrum of a metalloflavoprotein and has xanthine oxidase activity. 2. The enzyme responsible for the reduction cofractionates with hog liver xanthi...

The distribution of xanthine dehydrogenase throughout the soybean plant as well as the intercellular localization of xanthine dehydrogenase within soybean nodules was determined. Polyclonal antibodies against purified xanthine dehydrogenase were prepared and used in an enzymelinked immunosorbent assay to determine whether xanthine dehydrogenase is a nodule-specific protein. This immunological a...

xanthine oxidase plays crucial roles in the production of reactive oxygen species (ros), and uric acid in blood which may lead to gout, one of the oldest known forms of arthritis amongst humans. summer savory (satureja hortensis l.) a medicinal/spice exhibits antioxidant activity, but unknown effects on xanthine oxidase activity. here, for the first time, we examined the effects of s. hortensis...

1. The hypothesis was tested that the renal xanthine oxidase system provides a source of oxygen free radicals in puromycin aminonucleoside and adriamycin experimental nephrosis by generating uric acid from hypoxanthine and xanthine. 2. The concentrations in renal tissue of the putative intermediary products of puromycin aminonucleoside metabolism, hypoxanthine and xanthine, and of their precurs...

The corneas of albino rabbits were irradiated (5 min exposure once a day) with UVB rays (312 nm) for 4 days (shorter procedure) or 8 days (longer procedure). The eyes were examined microbiologically and only the corneas of sterile eyes or eyes with non-pathogenic microbes were employed. Histochemically, the activities of reactive oxygen species (ROS)-generating oxidases (xanthine oxidase, D-ami...

Prior reduction of chicken liver xanthine dehydrogenase with xanthine or NADH leads to accelerated loss of enzymic FAD on exposure to 3 M KI. Reduction with NADH leads to the dissociation of all of the FAD, whereas reduction with xanthine results in the rapid dissociation of only 50% of the FAD. In both cases the xanthine ---f NAD activity is completely abolished. Oxidation of xanthine in the p...

Urate lowering therapy in this country has mainly been achieved by the use of allopurinol and probenecid. A new xanthine oxidase inhibitor called febuxostat has been approved in 2009 for treatment of hyperuricaemia in gout. In this report, we describe the management of a patient with chronic tophaceous gout using febuxostat. The reduction in serum uric acid to target levels was rapid, and the t...

Oxygen free radicals generated by xanthine oxidase have been implicated in cardiac damage. The activity of xanthine oxidase/reductase in adult rat heart is considerable. Its assay gives controversial results for other species, for example, rabbits and humans. Therefore, we perfused isolated hearts of various species, including explanted human hearts, to measure the conversion of exogenous hypox...