Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P47989 (xanthine oxidase)
 8,633 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Differential effects of superoxide and hydroxyl radical on intracellular calcium were investigated in trout hepatoma cells (RTH-149). [Ca2+]i variations were recorded using confocal imaging, fluo-3 loading, and exposure to various mixtures consisting of hypoxanthine/xanthine oxidase (HX/XO), and of sub-stimulatory concentrations of H2O2 and Cu2+ . No [Ca2+]i variation was found with HX/XO, a slight [Ca2+]i rise with a mixture of Cu2+ and HX/XO, a sustained rise with Cu2+ and H2O2, and the highest rise with Cu2+, H2O2 and HX/XO. Fluorimetric assay using dihydrorhodamine 123 revealed a correlation between the oxidizing power of a mixture and its effect on [Ca2+]i. The [Ca2+]i rise induced by Cu2+, H2O2 and HX/XO, was partially reduced in Ca2+ free medium or in the presence of SOD, converted into Ca2+ transient by verapamil, and almost abolished by the PLC inhibitor U73122 or in the presence of the hydroxyl radical quencher TEMPOL. Data indicate that Ca2+ is mobilized by hydroxyl radical but not by superoxide. The mechanism consists of PLC activation causing intracellular Ca2+ release, while Ca2+ entry potentiates Ca2+ release thus leading to sustained [Ca2+]i rise. A role of hydroxyl radicals in the oxidative switching-on of Ca2+ signaling is discussed.
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PMID:Ca2+ is mobilized by hydroxyl radical but not by superoxide in RTH-149 cells: the oxidative switching-on of Ca2+ signaling. 1614 Mar 74

The purpose of this study is to compare the oxidative stress response to aerobic and anaerobic power testing, and to determine the impact of exercise training with or without glycine propionyl-L-carnitine (GPLC) in attenuating the oxidative stress response. Thirty-two subjects were assigned (double blind) to placebo, GPLC-1 (1g PLC/d), GPLC-3 (3g PLC/d) for 8 weeks, plus aerobic exercise. Aerobic (graded exercise test: GXT) and anaerobic (Wingate cycle) power tests were performed before and following the intervention. Blood was taken before and immediately following exercise tests and analyzed for malondialdehyde (MDA), hydrogen peroxide (H2O2), and xanthine oxidase activity (XO). No interaction effects were noted. MDA was minimally effected by exercise but lower at rest for both GPLC groups following the intervention (p = 0.044). A time main effect was noted for H2O2 (p = 0.05) and XO (p = 0.003), with values increasing from pre- to postexercise. Both aerobic and anaerobic power testing increase oxidative stress to a similar extent. Exercise training plus GPLC can decrease resting MDA, but it has little impact on exercise-induced oxidative stress biomarkers.
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PMID:Oxidative stress in response to aerobic and anaerobic power testing: influence of exercise training and carnitine supplementation. 1926 89