In 1948 Miller (1) demonstrated that the loss of liver xanthine oxidase activity in the rat greatly exceeded the loss of liver protein during acute inanition. Moreover, xanthine oxidase appeared to be the most labile of the four liver enzymes studied. Westerfeld and Richert (2) observed that increasing the level of protein in the diet tended to bring about an increase in liver xanthine oxidase ...

The present study was to evaluate the two aminomethyl derivatives of dehydrozingerone: 5-[(4-methylpiperazin-1-yl)methyl]dehydrozingerone and 5-(morpholin-4-ylmethyl)dehydrozingerone as lipoxygenase xanthine oxidase inhibitors. Nordihydroguaiaretic acid, allopurinol parent compound dehydrozingerone were used comparative compounds. Results indicated that 5-[(4-methylpiperazin-1-yl)methyl] 5-(mor...

The rate of reduction of 2,6-dichlorobenzenoneindophenol by xanthine oxidase plus its aldehydic or purine substrates is strikingly stimulated by the admixture of water-miscible organic solvents. In addition to acting as the electron acceptor in these assays, 2,6-dichlorobenzenoneindophenol is found to be a potent competitive inhibitor of xanthine oxidase with a K, of 1 X 10 6 M. The leuco form ...

The influence of dietary molybdenum on esophageal carcinogenesis induced by N-methyl-N-benzylnitrosamine (2.5 mg per kg of body weight once a week for 20 wk s.c.) was studied in male F344 rats. The tumor incidence and tumor development in the esophagus were significantly lower in the rats in the high-molybdenum (2 ppm) diet group than in the rats in the low-molybdenum (0.032 ppm) diet group; i....

The HPTLC analysis, antioxidant, and antigout activity of Asparagus racemosus, Withania somnifera, Vitex negundo, Plumbago zeylanica, Butea monosperma and Tephrosia purpurea extracts were investigated. The chemical fingerprinting were carried out by high performance thin layer chromatography (HPTLC), antioxidant activity by ABTS, DPPH, FRAP radical scavenging assays, and antiogout activity by c...

The quinimine form of p-aminophenol inhibits the oxygen uptake of tissue suspensions and in very small concentrations inhibits specifically the oxidation of hypoxanthine and xanthine to uric acid by the xanthine oxidase of liver (1). Closely related compounds such as o-aminophenol, p-phenylenediamine, and quinone, although they inhibit to different degrees the oxygen uptake of tissues, have no ...

Recent evidence in vivo indicates that spontaneously hypertensive rats (SHR) exhibit an increase in oxyradical production in and around microvascular endothelium. This study is aimed to examine whether xanthine oxidase plays a role in overproduction of oxidants and thereby may contribute to hypertensive states as a consequence of the increasing microvascular tone. The xanthine oxidase activity ...

Previous studies from this laboratory (1) have demonstrated the existence of several different types of “xanthine oxidase” in nature. The enzymes in milk and mammalian tissues appear to be quite similar, but can be differentiated by the inhibitor Antabuse, which affects only the tissue enzyme (2). Antabuse can also be used to separate the dehydrogenase and oxidase activities of tissue xanthine ...

Xanthine oxidase activity containing fractions from rat, mouse, rabbit and guinea pig livers were obtained by heat treatment and ammonium sulfate precipitation. Xanthine oxidase activity was observed in rat and mouse liver fractions, while xanthine oxidase activity was absent in rabbit and guinea pig liver fractions. Enzyme kinetic parameters, K m and V max , were determined for the conversion ...