Famciclovir, a 9-substituted guanine derivative, is a new antiviral agent which undergoes rapid hydrolysis and oxidation in man to yield the active antiherpes agent, penciclovir. Studies with human liver cytosol have indicated that the oxidation of the penultimate metabolite, 6-deoxypenciclovir, to penciclovir is catalyzed by the molybdenum hydroxylase, aldehyde oxidase. In the present study th...

BACKGROUND/AIMS Homovanillamine is a biogenic amine that it is catalyzed to homovanillyl aldehyde by monoamine oxidase A and B, but the oxidation of its aldehyde to the acid derivative is usually ascribed to aldehyde dehydrogenase and a potential contribution of aldehyde oxidase and xanthine oxidase is usually ignored. METHODS The present investigation examines the metabolism of homovanillami...

Fennel, Foeniculum vulgare Mill. (Apiaceae) is an aromatic plant, with medicinal and culinary applications, widely naturalized worldwide, especially near the see coasts and riversides. Fennel has long been used in Iran as a traditional remedy against gout. The objective of our study was to uncover the scientific basis of this traditional gout therapy. Different plant parts were extracted by met...

The products of the activity of xanthine oxidase (EC 1.2.3.2) include such reactive substances as H,O,, singlet oxygen and the superoxide and hydroxyl free radicals (KeUogg & Fridovich, 1975), which are currently receiving considerable attention not only because they lead to the formation of lipid hydroperoxides, but also because the latter may promote the formation of prostaglandins (Hemler et...

The influence of dietary protein on the activity of rat liver xanthine oxidase has been studied by several workers (l-5) and would point to a relationship between the availability of amino acids and the activity of liver xanthine oxidase (2). It has been demonstrated that the loss of liver xanthine oxidase activity in the rat greatly exceeds the loss of liver protein during acute inanition (l),...

Fetal brain hypoxic injury remains a concern in high-risk delivery. There is significant clinical interest in agents that may diminish neuronal damage during birth asphyxia, such as in allopurinol, an inhibitor of the prooxidant enzyme xanthine oxidase. Here, we established in a rodent model the capacity of allopurinol to be taken up by the mother, cross the placenta, rise to therapeutic levels...

Oxidative stress plays an important role in the progression of vascular endothelial dysfunction. The two major systems generating vascular oxidative stress are the NADPH oxidase and the xanthine oxidase pathways. Allopurinol, a xanthine oxidase inhibitor, has been in clinical use for over 40 years in the treatment of chronic gout. Allopurinol has also been shown to improve endothelial dysfuncti...

Heart failure is a clinical syndrome associated with elevated levels of oxygen-derived free radicals. Xanthine oxidase activity is believed to be one source of reactive oxygen species in the failing heart. Interventions designed to reduce oxidative stress are believed to have significant therapeutic potential in heart failure. This study tested the hypothesis that xanthine oxidase activity woul...

To examine the possible role of reactive oxygen metabolites in lymphocyte-mediated cytolysis, the morphology of cell death following the exposure of cells to reactive oxygen metabolites in vitro was compared with the morphology of cell-mediated killing in vitro of tumour cells by natural killer (NK) cells. Ultrastructural examination of human tumour cells that were dying following incubation fo...

Vascular smooth muscle cells (VSMCs) proliferate in response to arterial injury. Recent findings suggest that, in addition to platelet-derived growth factors, growth factors from inflammatory cells and endothelial cells at the site of injury may contribute to VSMC proliferation. We hypothesized that a common mechanism by which endothelial cells and inflammatory cells stimulate VSMC growth could...