The oxygen radical-producing enzyme xanthine oxidase (XO) can promote neutrophil adherence to endothelium. Recognizing that a balance often exists in inflammatory processes, we sought to determine whether XO initiates antiadherent pathways. We found that bovine pulmonary arterial endothelial cells (EC) exposed to XO released increased amounts of nitrite into the media, reflecting an increased p...

OBJECTIVES Oxidative stress plays an important role in the pathogenesis of multiple sclerosis (MS). Though reactive oxygen species (ROS) are produced by various mechanisms, xanthine oxidase (XO) is a major enzyme generating ROS in the context of inflammation. The objectives of this study were to investigate the involvement of XO in the pathogenesis of MS and to develop a potent new therapy for ...

The enzyme xanthine oxidase (XO) has been implicated in the pathogenesis of several disease processes, such as ischemia-reperfusion injury, because of its ability to generate reactive oxygen species. The expression of XO and its precursor xanthine dehydrogenase (XDH) is regulated at pre- and posttranslational levels by agents such as lipopolysaccharide and hypoxia. Posttranslational modificatio...

Excess reactive oxygen species (ROS) formation can trigger various pathological conditions such as inflammation, in which xanthine oxidase (XO) is one major enzymatic source of ROS. Although XO has been reported to play essential roles in inflammatory conditions, the molecular mechanisms underlying the involvement of XO in inflammatory pathways remain unclear. Febuxostat, a selective and potent...

The goal of this study was to determine the effects of peroxynitrite (ONOO-) on smooth muscle membrane potential and vasomotor function in rabbit carotid arteries. ONOO- is known to affect vascular tone by several mechanisms, including effects on K+ channels. Xanthine (X, 0.1 mM), xanthine oxidase (XO, 0.01 U/ml), and a low concentration of sodium nitroprusside (SNP, 10 nM) were used to generat...

Topical application of the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) to SENCAR mouse skin results within 48 h in a 3-fold elevation of xanthine oxidase (XO) activity, an enzyme capable of generating the reactive oxygen species superoxide and hydrogen peroxide. The antiinflammatory steroid fluocinolone acetonide, an inhibitor of TPA-induced hyperplasia, as well as the multiple st...

Topical application of the tumor promoter 12-0-tetradecanoylphorbol13-acetate (TPA) to SENCAR mouse skin results within 48 h in a 3-fold elevation of xanthine oxidase (XO) activity, an enzyme capable of gen erating the reactive oxygen species Superoxide and hydrogen peroxide. The antiinflammatory steroid fluocinolone acetonide, an inhibitor of TPAinduced hyperplasia, as well as the multiple sta...

Sauropus androgynus, Aerva lanata & Benincasa hispida have been using as leafy vegetable in kerala. The investigation undertaken was aimed to study xanthine oxidase (XO) inhibitory activity of these three plants and it was demonstrated the usefulness and beneficial effects in the treatment of Gout. Inhibition of XO is an effective therapeutic approach for treating hyperuricemia that causes gout...

Oxygen-derived free radicals are believed to contribute to reperfusion injury based, in part, upon results conferred by the pharmacologic administration of allopurinol. Allopurinol inhibits xanthine oxidase (XO) activity in ischemic tissues. The possible role of XO as a pathologic mediator prompted examination of its effects on isolated peripheral canine neutrophils. In contrast to neutrophils ...

Many cases of chromosomal mosaicism of the XO/XY type have been described. The phenotype of these patients has shown a wide diversity. In a recent review of 19 published cases in which the XO/XY sex chromosome pattern was established (Jackson, Hoffman, and Makda, 1966), 14 were apparently female and 5 male. The occurrence of XO/XYY mosaicism has been reported less often. Jacobs, Harnden, Buckto...