Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

N-acetylaspartic acid accumulates in Canavan Disease, a severe leukodystrophy characterized by swelling and spongy degeneration of the white matter of the brain. This inherited metabolic disease, caused by deficiency of the enzyme aspartoacylase, is clinically characterized by severe mental retardation, hypotonia and macrocephaly, and also generalized tonic and clonic type seizures in about half of the patients. Considering that the mechanisms of brain damage in this disease remain not fully understood, in the present study we investigated whether oxidative stress is elicited by N-acetylaspartic acid. The in vitro effect of N-acetylaspartic acid (10-80 mM) was studied on oxidative stress parameters: total radical-trapping antioxidant potential (TRAP), total antioxidant reactivity (TAR), chemiluminescence, thiobarbituric acid-reactive substances (TBA-RS), reduced glutathione content, sufhydryl content and carbonyl content in the cerebral cortex of 14-day-old rats. The effect of the acute administration of N-acetylaspartic acid (0.1-0.6 mmol/g body weight) was studied on TRAP, TAR, carbonyl content, chemiluminescence and TBA-RS. TRAP, TAR, reduced glutathione content and sulfhydryl content were significantly reduced, while chemiluminescence, TBA-RS and carbonyl content were significantly enhanced by N-acetylaspartic acid in vitro. The enhancement in TBA-RS promoted by N-acetylaspartic acid was completely prevented by ascorbic acid plus Trolox, and partially prevented by glutathione and dithiothreitol. The acute administration of N-acetylaspartic acid also significantly reduced TRAP and TAR, and significantly enhanced carbonyl content, chemiluminescence and TBA-RS. Our results indicate that N-acetylaspartic acid promotes oxidative stress by stimulating lipid peroxidation, protein oxidation and by decreasing non-enzymatic antioxidant defenses in rat brain. This could be another pathophysiological mechanism involved in Canavan Disease.
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PMID:N-acetylaspartic acid promotes oxidative stress in cerebral cortex of rats. 1760 35

Canavan disease is an autosomal recessive leukodystrophy characterized by excessive excretion of N-acetylaspartic acid (NAA) in urine. The disease is caused by deficiency of aspartoacylase, the enzyme responsible for the hydrolysis of NAA into acetate and l-aspartate. Patients, who are often asymptomatic in their early months, show a wide spectrum of clinical presentation thereafter that includes macrocephaly, poor head control, seizures, abnormal muscle tone, optic atrophy, significant developmental delay and death. In this work, we describe a simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of NAA in urine. The internal standard d3-NAA was added to untreated urine and the mixture was injected into the LC-MS/MS system operated in the negative ion mode. Detection was achieved in multiple reaction monitoring (MRM) mode by monitoring m/z 174 --> 88, 174 --> 130 and 174 --> 58 for NAA and 177 --> 89 for the internal standard. Separation was carried out on a C8 column (2.1 x 150 mm) using a mixture of acetonitrile and water (1:1 v/v) containing 0.05% formic acid at a flow rate of 0.25 ml/min. NAA was eluted at 1.6 min and the run time was approximately 2 min. Using spiked urine, the assay was linear up to 2 mmol/L with limit of quantification at 1 micromol/L (S/N = 12). NAA in patients' urine (n = 17) ranged between 366 and 21,235 mmol/mol creatinine compared to controls of <39 mmol/mol creatinine (n = 159). This LC-MS/MS method for NAA as described involved no extraction and no derivatization, showed no interference, and gave excellent recovery with low variability and short analytical time.
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PMID:Quantification of N-acetylaspartic acid in urine by LC-MS/MS for the diagnosis of Canavan disease. 1763 91

N-acetylaspartic acid (NAA) is the biochemical hallmark of Canavan Disease, an inherited metabolic disease caused by deficiency of aspartoacylase activity. NAA is an immediate precursor for the enzyme-mediated biosynthesis of N-acetylaspartylglutamic acid (NAAG), whose concentration is also increased in urine and cerebrospinal fluid of patients affected by CD. This neurodegenerative disorder is clinically characterized by severe mental retardation, hypotonia and macrocephaly, and generalized tonic and clonic type seizures. Considering that the mechanisms of brain damage in this disease remain not fully understood, in the present study we investigated whether intracerebroventricular administration of NAA or NAAG elicits oxidative stress in cerebral cortex of 30-day-old rats. NAA significantly reduced total radical-trapping antioxidant potential, catalase and glucose 6-phosphate dehydrogenase activities, whereas protein carbonyl content and superoxide dismutase activity were significantly enhanced. Lipid peroxidation indices and glutathione peroxidase activity were not affected by NAA. In contrast, NAAG did not alter any of the oxidative stress parameters tested. Our results indicate that intracerebroventricular administration of NAA impairs antioxidant defenses and induces oxidative damage to proteins, which could be involved in the neurotoxicity of NAA accumulation in CD patients.
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PMID:Intracerebroventricular administration of N-acetylaspartic acid impairs antioxidant defenses and promotes protein oxidation in cerebral cortex of rats. 1929 97

N-Acetylaspartic acid accumulates in Canavan Disease, a severe inherited neurometabolic disease clinically characterized by severe mental retardation, hypotonia, macrocephaly and generalized tonic and clonic type seizures. Considering that the mechanisms of brain damage in this disease remain poorly understood, in the present study we investigated the in vitro and in vivo effects of N-acetylaspartic acid on the activities of catalase, superoxide dismutase and glutathione peroxidase, as well as on hydrogen peroxide concentration in cerebral cortex of 14-day-old rats. Catalase and glutathione peroxidase activities were significantly inhibited, while hydrogen peroxide concentration was significantly enhanced by N-acetylaspartic acid both in vitro and in vivo. In contrast, superoxide dismutase activity was not altered by N-acetylaspartic acid. Our results clearly show that N-acetylaspartic acid impairs the enzymatic antioxidant defenses in rat brain. This could be involved in the pathophysiological mechanisms responsible for the brain damage observed in patients affected by Canavan Disease.
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PMID:N-acetylaspartic acid impairs enzymatic antioxidant defenses and enhances hydrogen peroxide concentration in rat brain. 2043 87

A 3-year-old boy was admitted with psychomotor delay, spasticity, progressive visual loss, nystagmus, macrocephaly, and epileptic seizures for diagnostics. Cranial magnetic resonance imaging (MRI) revealed leukodystrophy and multicystic changes. Urine excretion of N-acetylaspartic acid was grossly increased, suggesting Canavan disease. Mutation screening of the ASPA gene confirmed this diagnosis. The underlying enzymatic defect causes accumulation of N-acetylaspartic acid and subsequent progressive myelin degeneration with characteristic spongy degeneration of the subcortical white matter, normally only seen histologically. We describe this case to show that spongy degeneration in Canavan disease may also be present macroscopically in the form of multiple beaded periventricular cysts on cranial MRI.
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PMID:Leukodystrophy with multiple beaded periventricular cysts: unusual cranial MRI results in Canavan disease. 2564 44