Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002736 (amyotrophic lateral sclerosis)
 19,048 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To evaluate reports of abnormal levels of free amino acids (AA) in patients with amyotrophic lateral sclerosis (ALS), we studied serum, cerebrospinal fluid, and urine AA in 12 patients with ALS and 12 controls matched for age, sex, and severity of disability. ALS patients had statistically significant elevations in serum levels of tyrosine, total aromatic AA, and total basic AA. ALS patients also had statistically significant elevations in cerebrospinal fluid of total basic AA, lysine, essential AA, and leucine. The severity of ALS correlated inversely with acidic AA (glutamate and aspartate) and O-phosphoserine in cerebrospinal fluid. Activity of ALS correlated directly with serum aspartate and cerebrospinal fluid alanine. We conclude that subtle abnormalities of AA levels are present in ALS and that these are not due to age, sex, or disability. The pattern of distribution of AA levels differs from that in hepatic or renal disease and suggests defective membrane transport or poor cellular utilization of basic and essential AA in the central nervous system.
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PMID:Free amino acid levels in amyotrophic lateral sclerosis. 66 70

We measured the levels of amino acids in biopsied skin from eight patients with amyotrophic lateral sclerosis (ALS) and seven controls. The most conspicuous changes in ALS patients were as follows. First, the contents of the acidic amino acids glutamate and aspartate were significantly decreased in ALS, and were negatively and significantly associated with the duration of illness. Second, the levels of the collagen-associated amino acids hydroxyproline, proline, glycine, alanine, and hydroxylysine were significantly decreased in ALS, and correlated inversely with the duration of illness. These results suggest that there are abnormalities of acidic amino acids and collagen-associated amino acids in the skin of patients with ALS. These changes may underlie the pathogenesis of ALS.
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PMID:Glutamate and aspartate are decreased in the skin in amyotrophic lateral sclerosis. 821 62

beta-N-Methylamino-L-alanine (BMAA) is a neurotoxic plant amino acid that has been implicated in the pathogenesis of the high incidence amyotrophic lateral sclerosis and related parkinsonism dementia of the western Pacific. Previous studies have demonstrated that BMAA is taken up into brain following intravenous or oral administration. To examine the kinetics and mechanism of brain transfer, BMAA influx across the blood-brain barrier was measured in rats using an in situ brain perfusion technique. BMAA influx was found to be saturable with a maximal transfer rate (Vmax) of 1.6 +/- 0.3 x 10(-3) mumol/s/g and a half-saturation constant (Km) of 2.9 +/- 0.7 mM based on total perfusate BMAA concentration. Uptake was sodium independent and inhibitable by excess L-leucine, but not by L-lysine, L-glutamate, or methylaminoisobutyric acid, indicative of transfer by the cerebrovascular large neutral amino acid carrier. L-BMAA competitively reduced brain influx of L-[14C]leucine, as expected for cross-inhibition. The results demonstrate that BMAA is taken up into brain by the large neutral amino acid carrier of the blood-brain barrier and suggest that uptake may be sensitive to the same factors that affect neutral amino acid transport, such as diet, metabolism, disease, and age.
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PMID:Facilitated transport of the neurotoxin, beta-N-methylamino-L-alanine, across the blood-brain barrier. 154 67

Exposure to cycad seed kernel is an etiologic factor for the western Pacific amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia complex (PDC). Traditionally processed cycad flours (n = 17) obtained from Chamorro residents of Guam and the adjacent island of Rota at risk for neurodegenerative disease were extracted and analyzed by high-performance liquid chromatography for content of beta-N-methylamino-L-alanine (BMAA) and methyl-azoxymethanol beta-D-glucoside (cycasin). Cycasin (detection limit: picomole) was present in concentrations of 0.004 to 75.93 micrograms/g (mean, 12.45 +/- 5.0 micrograms/g), and levels of BMAA (detection limit: subpicomole) ranged from 0.00 to 18.39 micrograms/g (mean, 5.44 +/- 1.56 micrograms/g). On average, cycasin content was approximately 10 times higher than that of BMAA. The largest concentrations of cycasin were found in samples from villages with a high reported prevalence of ALS/PDC. Ingestion of cycad-derived food would result in estimated human exposure to milligram amounts of cycasin per day. The cytotoxic properties of cycasin merit consideration in relation to the etiology of western Pacific ALS/PDC.
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PMID:Content of the neurotoxins cycasin (methylazoxymethanol beta-D-glucoside) and BMAA (beta-N-methylamino-L-alanine) in cycad flour prepared by Guam Chamorros. 162 Mar 43

Reductions in glutamate and aspartate contents, together with increased contents of taurine, have been observed in the autopsied brains and spinal cords of patients who have died with amyotrophic lateral sclerosis (ALS). The wobbler mouse develops an inherited degeneration of motoneurons within the brainstem and spinal cord, and has been proposed as an animal model of ALS. In symptomatic wobbler mice we found brain contents of glutamate, aspartate, and taurine similar to those in unaffected littermates, while brain contents of glutamine were increased, and those of serine and alanine were decreased. Spinal cords of wobbler mice had slightly decreased contents of glutamate, aspartate and glycine compared to normal littermates. Abnormalities of amino acid contents in the nervous system of wobbler mice are dissimilar to those in ALS patients suggesting a different pathogenesis of motoneuron loss.
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PMID:The wobbler mouse: amino acid contents in brain and spinal cord. 191 46

We evaluated glutamine synthetase (GS) and alanine aminotransferase (GPT) activities in biopsied muscle from 40 cases of various neuromuscular diseases. GS and GPT catalyze the synthesis of glutamine and alanine, respectively, from amino acids derived in part from the breakdown of muscle proteins. The subjects were 7 cases of muscular dystrophy; 1 Duchenne type (DMD), 3 limb-girdle type, 2 facioscapulohumeral type (FSH), 1 Fukuyama type (FCMD); and 1 myotonic dystrophy (MyD); 5 mitochondrial myopathies; 11 inflammatory myopathies including 6 polymyositis and 3 myopathy associated with collagen disease; 5 endocrinological myopathies including 2 periodic paralysis; and, 11 cases of neurogenic amyotrophies [4 amyotrophic lateral sclerosis (ALS), 4 spinal progressive muscular atrophy (SPMA) and 3 other types]. Control subjects were 8 patients with thigh operations. Biopsied muscle was homogenized and assayed for GS activity by the method of Smith et al.; GPT was assayed by commercial kit. Protein was assayed by the method of Lowry et al. Enzyme activities between mean -2SD and mean +2SD of controls were considered to be the normal range. GS activity in control subjects was 28.22 +/- 7.13 (mean +/- SD) nmol glutamine formed/mg protein/hr. Fifteen of 40 cases showed increased enzyme activity, including DMD and FCMD, the acute phase of polymyositis, and periodic paralysis. GPT activity in controls was 16.56 +/- 4.05 IU/mg protein. Sixteen of 40 patients showed increased enzyme activity: FCMD, FSH, MyD, inflammatory and endocrinological myopathy, and ALS. On the other hand, mitochondrial myopathy showed significantly decreased activity.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Studies on enzyme activities relating to amino acid mobilization in biopsied muscles]. 198 Jun 44

Concentrations of glutamic acid have been reported to be elevated in fasting plasma and cerebrospinal fluid (CSF) of patients with amyotrophic lateral sclerosis (ALS); glycine concentrations have also been reported to be increased in the CSF of such patients. Autopsy studies have shown glutamate contents to be significantly decreased in brain and spinal cord in ALS. These observations suggested that a systemic abnormality of glutamate metabolism might underlie the pathogenesis of ALS. We report here the findings of our studies of amino acid concentrations in patients with the sporadic form of ALS. Glutamate concentrations were normal in the fasting plasma of a great majority of the patients with ALS. Concentrations of glutamate, aspartate, and glycine were normal in the CSF of all 17 patients examined. beta-N-Methylamino-L-alanine, a plant neurotoxin possibly responsible for causing the Guamanian form of ALS, was not detectable in the plasma or CSF of any of our patients. Our findings do not lend support to the hypothesis that the sporadic form of ALS results from overexcitation of motor neurons by excitatory amino acids.
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PMID:Amyotrophic lateral sclerosis: amino acid levels in plasma and cerebrospinal fluid. 237 40

Recent studies have implicated the ingestion of the structurally related plant excitotoxins, beta-N-methylamino-L-alanine (BMAA), and beta-N-oxalylamino-L-alanine (BOAA), in the pathogenesis of two human motor system diseases, the amyotrophic lateral sclerosis-Parkinsonism-dementia complex of Guam (Guam ALS-PD), and lathyrism, respectively. We have investigated the toxicity of these amino acids on cultured mouse cortical neurons in the presence of physiological concentrations of bicarbonate (a required toxic cofactor for BMAA neurotoxicity). A 24 h exposure to 10 microM - 3 mM BMAA, or to 300 nM - 100 microM BOAA, induced, concentration-dependent neuronal degeneration without glial damage; the neurotoxic EC50 for BMAA was about 1 mM, and the EC50 for BOAA was about 20 microM. At high concentrations, both compounds destroyed essentially the entire neuronal population. Neurotoxicity also depended on exposure duration, with reduced injury at an exposure time of 1 h, and increased injury at an exposure time of 3 days. Despite the fact that ingestion of BMAA and BOAA both lead to motor system damage, previous studies have suggested that the two excitotoxins act primarily on different glutamate receptor subtypes: BMAA on N-methyl-D-aspartate (NMDA) receptors, and BOAA on non-NMDA receptors. Consistent with these studies, the neurotoxicity of high concentrations of BMAA was substantially attenuated by 1 mM D-amino-5-phosphonovalerate (D-APV), whereas BOAA neurotoxicity was less sensitive to D-APV but was attenuated by 2 mM kynurenate.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Neurotoxicity of beta-N-methylamino-L-alanine (BMAA) and beta-N-oxalylamino-L-alanine (BOAA) on cultured cortical neurons. 255 52

beta-N-methylamino-L-alanine (BMAA) is a neurotoxic glutamate agonist possibly responsible for the neuronal degeneration found in the Guam amyotrophic lateral sclerosis-Parkinsonism-dementia complex. The basis for glutamate receptor activation by BMAA has been unclear, as BMAA lacks the omega electronegative moiety characteristic of other excitatory amino acids. We recently reported that the neuroexcitatory and neurotoxic effects of BMAA depend strongly on the presence of bicarbonate ions and proposed that an interaction between bicarbonate and the beta amino group of BMAA produces a molecular configuration appropriate for activating glutamate receptors. We now report that bicarbonate potentiates the ability of BMAA to open NMDA receptor-activated channels in isolated membrane patches. Furthermore, the neurotoxic and neuroexcitatory effects of two structural analogs of BMAA, DL-2,4-diaminobutyrate and DL-2,3-diaminopropionate, were also potentiated by bicarbonate. These findings support the bicarbonate cofactor hypothesis for BMAA action and provide direct evidence that it may be generalizable to certain other compounds.
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PMID:Bicarbonate dependence of glutamate receptor activation by beta-N-methylamino-L-alanine: channel recording and study with related compounds. 256 69

Repeated dietary consumption of the neurotoxic amino acid beta-N-methylamino-L-alanine (BMAA), found in the seeds of Cycas circinalis, has been postulated as causing both amyotrophic lateral sclerosis (ALS) and the parkinsonism-dementia syndrome (PD) that were formerly very prevalent among the indigenous people of the Marianas Islands. Cynomolgus monkeys fed BMAA have been reported to develop behavioral and neuropathological changes like those found in human ALS. We gave large amounts of BMAA, totaling 15.5 g/kg of the L-isomer, by gavage to mice over 11 weeks without observing any behavioral abnormalities. When killed, these animals showed none of the neurochemical or neuropathological changes that would be expected in ALS or Parkinson's disease. Their striatal dopamine contents were normal, and there were no reductions in the contents of glutamate and aspartate in cerebral cortex like those encountered in sporadic human ALS. The results of this experiment do not support chronic ingestion of BMAA as the causative factor for Guamanian ALS or PD.
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PMID:Beta-N-methylamino-L-alanine. Chronic oral administration is not neurotoxic to mice. 261 65


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