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

Clinical evidence has suggested that mitomycin C (MMC) potentiates doxorubicin (DOX) induced cardiotoxicity. In this study a mouse model was used to examine the effect of DOX on the ability of cardiac tissue to bioactivate MMC to generate oxygen radicals. Cardiac damage was assessed by measuring serum CPK-MB isoenzyme levels and thiobarbituric acid reactive substances (TBARS) in the cardiac tissue. The exposure of animals to DOX or DOX and MMC over a three week period led to an increase in serum CPK-MB isoenzyme levels as well as TBARS. Treatment with DOX led to an increase in MMC-dependent, NADH-dependent, cyanide insensitive oxygen consumption, compared to control animals, thereby suggesting increased MMC-dependent oxygen radical generation. Levels of xanthine oxidase (XO; EC 1.1.3.22) and NADPH:cytochrome C reductase, two enzymes known to bioactivate MMC with subsequent oxygen radical generation, were measured in cardiac tissue with a 4.5 x increase in XO activity seen in DOX treated animals vs controls and no change in NADPH:cytochrome C reductase activity. Cardiac levels of xanthine dehydrogenase (XDH; EC 1.1.1.204) activity in DOX treated animals decreased while the XO/XDH ratio increased, suggesting a conversion of XDH to XO following DOX treatment.
 ...
PMID:Role of xanthine oxidase in the potentiation of doxorubicin-induced cardiotoxicity by mitomycin C. 191 Oct 46

Rat left atria or Langendorff hearts were kept at 37 degrees C and stimulated at a rate of 3.33 Hz. They were subjected to hypoxia (deprivation of oxygen) or ischemia (deprivation of oxygen and glucose + acidosis + increased extracellular potassium concentration) for 15 min or 1 h and subsequent reoxygenation for 5 or 15 min. Tissue concentrations of proteins, reduced and oxidized glutathione and conjugated dienes were measured at the end of the experiment. Hypoxia and ischemia decreased the excitability and contractility of the preparations and caused contracture. These effects were partly reversible during reoxygenation. However, in Langendorff hearts reoxygenation caused an increased release of CPK, LDH and glutathione into the perfusion fluid. Ischemia and reoxygenation in atria lowered the tissue concentration of reduced glutathione and increased its oxidized form. Similar changes were seen in atria and Langendorff hearts when oxygen radical production was accelerated by hypoxanthine and xanthine oxidase. No treatment raised significantly the concentration of conjugated dienes. These results seem to exclude an important role of an increased lipid peroxidation for reperfusion injury of isolated heart preparations.
 ...
PMID:No evidence for an increased lipid peroxidation during reoxygenation in Langendorff hearts and isolated atria of rats. 279 63

Oxidative stress has been shown to increase after acute myocardial infarction and during coronary reperfusion. Allopurinol inhibits xanthine oxidase, an enzyme involved in reperfusion injury. In this study, 40 patients with ST elevation myocardial infarction and symptoms' onset 3-12 h, who underwent primary coronary intervention, were administered either allopurinol (loading dose 400 mg followed by 100 mg for 1 month--group A, 21 patients), or placebo (group B). Allopurinol resulted in a more effective ST-E recovery (P<0.05 for all comparisons) and lower peak values of troponin I (P=0.04), CPK (P=0.01) and CK-MB (P=0.03). After 1-month follow-up period, 13% lower incidence of major adverse cardiac events (P=0.002) was also observed in group A, whereas no significant differences in the EF were detected between the groups studied. In our study population, allopurinol administration was beneficial concerning tissue reperfusion, myocardial injury and clinical outcomes.
 ...
PMID:The prognostic impact of allopurinol in patients with acute myocardial infarction undergoing primary percutaneous coronary intervention. 1977 63