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)

The efflux of hypoxanthine and uric acid from skeletal muscle has been noted to follow exercise and metabolic stress both in vivo and in vitro. Since the action of xanthine oxidase and hypoxanthine generates free radicals with potential damaging effect on the muscle membranes, an in vitro model was used to study the relationship of metabolic stress, oxypurine release and muscle contraction. When rat epitrochlearis muscle was exposed to the mitochondrial uncoupler dinitrophenol at 37 degrees C, lactate release was pronounced and hypoxanthine and uric acid appeared in the incubating medium. The twitch tension, in response to supramaximal stimulation, was reduced to less than 5% of the initial value. When the same experiment was repeated at 27 degrees C, hypoxanthine and uric acid formation was inhibited, although lactate release indicated that metabolic stress was still present. Twitch tension was relatively preserved (57% of the initial value). The lower temperature did not alter the decrease in ATP and phosphocreatine levels in the muscle which is produced by dinitrophenol. There was an inverse relationship between oxypurine release and twitch tension in individual muscles (r = 0.80, P < 0.01 for hypoxanthine and r = 0.95, P < 0.0002 for uric acid). Xanthine dehydrogenase/xanthine oxidase was detected in muscle and between 16 and 22% of the activity was in the oxidase form.
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PMID:Relationship of oxypurine release to contractile failure in dinitrophenol-treated rat skeletal muscle. 831 Aug 32

Molybdenum cofactor deficiency (MoCD) is a rare metabolic disorder characterized by severe and rapidly progressive neurologic damage caused by the functional loss of sulfite oxidase, 1 of 4 molybdenum-dependent enzymes. To date, no effective therapy is available for MoCD, and death in early infancy has been the usual outcome. We report here the case of a patient who was diagnosed with MoCD at the age of 6 days. Substitution therapy with purified cyclic pyranopterin monophosphate (cPMP) was started on day 36 by daily intravenous administration of 80 to 160 microg of cPMP/kg of body weight. Within 1 to 2 weeks, all urinary markers of sulfite oxidase (sulfite, S-sulfocysteine, thiosulfate) and xanthine oxidase deficiency (xanthine, uric acid) returned to almost normal readings and stayed constant (>450 days of treatment). Clinically, the infant became more alert, convulsions and twitching disappeared within the first 2 weeks, and an electroencephalogram showed the return of rhythmic elements and markedly reduced epileptiform discharges. Substitution of cPMP represents the first causative therapy available for patients with MoCD. We demonstrate efficient uptake of cPMP and restoration of molybdenum cofactor-dependent enzyme activities. Further neurodegeneration by toxic metabolites was stopped in the reported patient. We also demonstrated the feasibility to detect MoCD in newborn-screening cards to enable early diagnosis.
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PMID:Successful treatment of molybdenum cofactor deficiency type A with cPMP. 2038 44