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)

Cooxidative metabolism of the urinary bladder carcinogen N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide (FANFT) was examined using solubilized and particulate microsomal preparations from the rabbit renal inner medulla and the ram seminal vesicle. Metabolism was measured by the rate of decrease in absorbance at 400 nm. In these soluble and particulate preparations, FANFT metabolism was observed only in the presence of specific fatty acids. These fatty acids are substrates for prostaglandin endoperoxide synthetase. Structurally dissimilar inhibitors of prostaglandin endoperoxide synthetase such as indomethacin, aspirin, 5,8,11,14-eicosatetraynoic acid, ethoxyquin, and meclofenamic acid specifically inhibited FANFT metabolism. Other inhibitor and substrate specificity studies suggest that FANFT was not metabolized by nitroreductase, xanthine oxidase, lipoxygenase, lipid peroxidation, or mixed-function oxidases. In addition, the lack of detectable 2-amino-4-(5-nitro-2-furyl)thiazole formation suggests that arylformamidase was not participating in FANFT metabolism measured in these experiments. The data indicate that prostaglandin endoperoxide synthetase can mediate FANFT metabolism by a cooxidative process.
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PMID:Metabolism of N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide by prostaglandin endoperoxide synthetase. 676 14

The effects of aspirin on N-[4-(5-nitro-2-furyl)-2-thiazolyl]-formamide (FANFT) -induced urinary bladder lesions, endogenous bladder prostaglandin E2 synthesis, and the metabolism of FANFT by bladder epithelial microsomes were examined. Rats were fed 0.5% aspirin and/or a diet containing 0.1% or 0.2% FANFT. Bladder lesions were observed with light and scanning electron microscopy, and the prostaglandin E2 content of rat bladder was measured by radioimmunoassay. Metabolism of FANFT was measured by decreased absorbance at 400 nm. Aspirin inhibited the appearance of hyperplastic lesions induced by feeding 0.1% or 0.2% FANFT for 6 or 12 weeks. Aspirin reduced bladder prostaglandin E2 content at 1, 2, 6, and 13 weeks compared to corresponding control values. Rat and rabbit microsomal metabolism of FANFT were dependent upon specific fatty acid substrate and prevented by specific inhibitors (including aspirin) of prostaglandin endoperoxide synthetase. Other inhibitor and substrate specificity studies suggest that FANFT was not metabolized by xanthine oxidase, lipoxygenase, lipid peroxidation, or mixed-function oxidases. These results suggest that the metabolism of FANFT by prostaglandin endoperoxide synthetase may be involved in the metabolic activation of FANFT necessary for the induction of bladder cancer in rats.
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PMID:Aspirin inhibition of N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide-induced lesions of the urinary bladder correlated with inhibition of metabolism by bladder prostaglandin endoperoxide synthetase. 679 Jan 63