Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030567 (Parkinson's disease)
 63,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sebum secretion was measured on the forehead of 47 patients with Parkinson's disease before and after treatment with anticholinergic (biperiden), levodopa + AAID and bromocriptine, by the osmic acid technique. Another 100 patients under biperiden, levodopa + AAID or association of both, for at least one year, were also evaluated. The male parkinsonian "de novo" patients have shown greater sebum secretion than female patients. It was also concluded that biperiden failed to reduce sebum secretion rate. On the other hand, it was found that L-dopa + AAID reduces the sebum secretion (CL = casual level and SER = sebum excretion rate) on both male and female patients. Bromocriptine (10mg/day) was the second dopaminergic therapy employed in the present work. Similarly to L-dopa, this dopaminergic agonist was able to significantly reduce sebum secretion (both CL and SER) of male patients. There was a positive and significant correlation for the 50-59 years old male patients "de novo" between CL and tremor, hypokinesia, gait and posture or functional incapacity, before treatment. After a period of treatment correlation was no more found. In relation to parkinsonians under chronic treatment was found a positive and significant correlation between sebum secretion and hypokinesia. The level of sebum secretion on parkinsonian "de novo" patients before treatment was equal to parkinsonian patients under chronic treatment regardless the treatment, except for greater than or equal to 60 years old parkinsonians who have shown CL and SER higher than "de novo" parkinsonian patients with the same age but without treatment. The treatment with L-dopa + AAID significantly decreased both CL and SER of "de novo" parkinsonian patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[L-dopa, biperiden and sebum excretion in Parkinson disease]. 276 50

The incorporation of labelled carbon from glucose U-14C into CSF amino acids was investigated in three patients with Parkinson's disease and in three control persons with comparable age and physical stature. Comparing the specific radioactivities of serum and CSF one can postulate that the labelled amino acids found in the CSF are synthesized mainly by brain tissue. The resorption of glucose into the CNS and therefore the synthesis of amino acids from glucose was more rapid in controls; labelled alanine and glutamine appeared later in the CSF of the patients. As expected, in the controls the specific radioactivity of glutamic acid was found to be higher than that of glutamine, in patients the labelling of glutamine was higher as was that of serine, glycine, aspartic acid and asparagine. From our knowledge concerning the compartmentation of the metabolism of glutamate, we assume that in Parkinsonism the metabolic activity of neurons is reduced but that of astroglia is enhanced.
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PMID:[Biosynthesis of amino acids from glucose in the central nervous system in the Parkinson syndrome]. 665 3

Bernserazide (D,L-serine 2-[2,3,4-trihydroxybenzyl]-hydrazide) as been shown to inhibit the clorgyline-resistant amine oxidase (CRAO) activities which metabolize benzylamine in homogenates of rat aorta, heart and brown adipose tissue. In vitro studies showed a concentration- and time-dependent inhibition of CRAO in heart and aorta which was reversed by dialysis for 18hr. At high concentrations (10(-4)-10(-3)M) benserazide appeared to increase enzyme activity towards and occasionally above control value. These increases became more prominent after long periods of preincubation (especially in the presence of saturating benzylamine concentrations) and remained after dialysis of those homogenates preincubated with benserazide. The administration of benserazide for one or seven days in daily doses of 5-150 mg/kg also inhibited CRAO activity in vivo in a dose-dependent manner, with greater inhibition after seven days treatment. Reversal of inhibition, by dialysis of tissue homogenates from benserazide-treated rats, was much slower than was found with homogenates incubated in vitro with the drug. After benserazide administration to rats, MAO-A activity towards 5-hydroxytryptamine was generally not inhibited, and in fact was significantly increased in some cases. The administration of L-DOPA (250 mg/kg) together with benserazide (40 mg/kg) resulted in a similar degree of CRAO inhibition in aorta and heart to that seen after benserazide alone. These findings are discussed with regard to the use of these drugs in the therapy of Parkinson's Disease, although the paucity of information about the physiological function of CRAO makes the significance of its inhibition by benserazide unclear.
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PMID:In vitro and in vivo inhibition by benserazide of clorgyline-resistant amine oxidases in rat cardiovascular tissues. 709 30

Aromatic alpha-amino-alpha-methyl acids and alpha-hydrazino-alpha-methyl acids are known aromatic amino acid decarboxylase inhibitors. Specific derivatives such as 2-amino-2-methyl-3-(3,4- dihydroxyphenyl)propanoate, Aldomet, and 2-hydrazino-2-methyl-3-(3,4- dihydroxyphenyl)propanoate, Lodosyn, have been developed as therapeutic agents to treat hypertension and Parkinson's disease, respectively. We recently reported a method for the kinetic resolution of the racemic esters of such compounds using a crude preparation of a novel enzyme catalyst from the yeast Candida lipolytica (Yee, C.; Blythe, T.A., McNabb, T.J.; Walts, A.E. J. Org. Chem. 1992, 57, 3525-3527). Here we report the purification and initial characterization of the active enzyme component, an enzyme given the name Candida lipolytica ester hydrolase (CLEH). CLEH was purified to > 95% homogeneity by chromatography on Matrex Blue B resin. The enzyme was found to be a glycoprotein with M(r) = 80,000-300,000. In addition to esterolytic activity, the enzyme was found to catalyze the hydrolysis of amides, anilides and peptides. Sequence analysis of internal peptides of CLEH revealed striking homology to a number of enzymes belonging to the group of serine carboxypeptidases (E.C. 3.4.16.1). One peptide aligned with the canonical serine carboxypeptidase active site sequence, GESYAG. Based on the structural relationship of CLEH to serine carboxypeptidases, three representative serine carboxypeptidases were evaluated for their utility in resolving racemic alpha-tertiary ester substrates and compared with the activity of CLEH. All enzymes revealed similarly high activity and enantioselectivity towards the alpha-hydrazino-alpha-methyl ester precursor of the Parkinson-drug Carbidopa. However, differences in enantioselectivity were observed with other alpha-tertiary-substituted ester substrates. Serine carboxypeptidase-catalyzed ester resolutions thus offer a new route to many sterically hindered homochiral alpha-amino, alpha-hydrazino and alpha-hydroxy carboxylic acids.
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PMID:Enzymes for the resolution of alpha-tertiary-substituted carboxylic acid esters. 785 60

Rats were treated intraperitoneally with a mixture of 250 mg/kg L-DOPA and 40 mg/kg carbidopa or with vehicle and sacrificed 30 min later. Plasma, heart and cortex, midbrain, brainstem and cerebellum were removed from each animal and assayed by HPLC for L-DOPA and a large number of amino acids and related amino compounds. L-DOPA levels increased from undetectable (<0.2 nmol/ml or g) to 1,146, 1,007, 399, 376, 368 and 850 nmol/ml or g in the above tissues. In addition, several amino compounds were significantly affected by L-DOPA/carbidopa (p < or = 0.01). Plasma concentrations of phosphoserine, oxidized glutathione, citrulline, phenylalanine, tyrosine and 1-methylhistidine increased and arginine, glutamic acid and lysine decreased. In the heart, concentrations of phosphoserine, taurine, reduced glutathione, threonine, serine, glutamine, glycine, alanine, valine, GABA, ethanolamine, ammonia and arginine decreased. In the cortex, camosine and homocarnosine increased. In the midbrain, valine increased and leucine, ornithine and oxidized glutathione decreased. In the cerebellum, citrulline increased. In the brainstem, threonine, serine, asparagine, glutamine, oxidized glutathione, alanine, and leucine decreased. In the brainstem, arginine was slightly decreased with a concomitant increase in citrulline (p < 0.05), indicative of nitrous oxide formation. These results show that administration of L-DOPA/ carbidopa not only raises dopamine levels but can also affect other biochemicals and that the observed changes in amino acids and related compounds can perhaps contribute to the beneficial and/or adverse effects of L-DOPA/carbidopa therapy of Parkinson's disease.
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PMID:Effects of L-DOPA/carbidopa administration on the levels of L-DOPA, other amino acids and related compounds in the plasma, brain and heart of the rat. 934 99

The neurotransmitter serotonin has been implicated in numerous physiological functions and pathophysiological disorders. The hydroxylation of the aromatic amino acid tryptophan is rate-limiting in the synthesis of serotonin. Tryptophan hydroxylase (TPH), as the rate-limiting enzyme, determines the concentrations of serotonin in vivo. Relative serotonin concentrations are clearly important in neural transmission, but serotonin has also been reported to function as a local antioxidant. Identification of the mechanisms regulating TPH activity has been hindered by its low levels in tissues and the instability of the enzyme. Several TPH expression systems have been developed to circumvent these problems. In addition, eukaryotic expressions systems are currently being developed and represent a new avenue of research for identifying TPH regulatory mechanisms. Recombinant DNA technology has enabled the synthesis of TPH deletions, chimeras, and point mutations that have served as tools for identifying structural and functional domains within TPH. Notably, the experiments have proven long-held hypotheses that TPH is organized into N-terminal regulatory and C-terminal catalytic domains, that serine-58 is a site for PKA-mediated phosphorylation, and that a C-terminal leucine zipper is involved in formation of the tetrameric holoenzyme. Several new findings have also emerged regarding regulation of TPH activity by posttranslational phosphorylation, kinetic inhibition, and covalent modification. Inhibition of TPH by L-DOPA may have implications for depression in Parkinson's disease (PD) patients. In addition, TPH inactivation by nitric oxide may be involved in amphetamine-induced toxicity. These regulatory concepts, in conjunction with new systems for studying TPH activity, are the focus of this article.
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PMID:Advances in the molecular characterization of tryptophan hydroxylase. 977 Jun 40

alpha-Synuclein has been implicated in the pathogenesis of several neurodegenerative disorders based on the direct linking of missense mutations in alpha-synuclein to autosomal dominant Parkinson's disease and its presence in Lewy-like lesions. To gain insight into alpha-synuclein functions, we have investigated whether it binds neuronal proteins and modulates their functional state. The microtubule-associated protein tau was identified as a ligand by alpha-synuclein affinity chromatography of human brain cytosol. Direct binding assays using (125)I-labeled human tau40 demonstrated a reversible binding with a IC(50) about 50 pM. The interacting domains were localized to the C terminus of alpha-synuclein and the microtubule binding region of tau as determined by protein fragmentation and the use of recombinant peptides. High concentrations of tubulin inhibited the binding between tau and alpha-synuclein. Functionally, alpha-synuclein stimulated the protein kinase A-catalyzed phosphorylation of tau serine residues 262 and 356 as determined using a phospho-epitope-specific antibody. We propose that alpha-synuclein modulates the phosphorylation of soluble axonal tau and thereby indirectly affects the stability of axonal microtubules.
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PMID:alpha-synuclein binds to Tau and stimulates the protein kinase A-catalyzed tau phosphorylation of serine residues 262 and 356. 1046 79

A variety of deletional and point mutations has been identified in the parkin gene on chromosome 6q25.2-27 in patients with autosomal recessive juvenile parkinsonism, a distinct form of familial Parkinson's disease (PD). To study the potential involvement of the parkin gene in development of non-hereditary idiopathic PD, a codon 167 serine/asparagine (167S/N) polymorphism located in its exon 4 was analyzed by direct sequencing in 71 patients with sporadic PD and 109 age-matched non-PD controls. The frequency of either 167S or 167N allele was not statistically different between PD patients and controls, while the frequency of 167S/N heterozygotes was significantly higher in PD patients (62.0% vs 45.9%), compared with that of both 167S/S and 167N/N homozygotes combined (chi2 4.467, p = 0.0346; odds ratio = 1.92, 95% confidence interval = 1.05-3.54). These observations suggest that the heterozygosity at codon 167 in the parkin gene might represent a genetic risk factor for development of sporadic PD.
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PMID:Association of codon 167 Ser/Asn heterozygosity in the parkin gene with sporadic Parkinson's disease. 1051 32

alpha-Synuclein has been implicated in the pathogenesis of Parkinson's disease, since rare autosomal dominant mutations are associated with early onset of the disease and alpha-synuclein was found to be a major constituent of Lewy bodies. We have analyzed alpha-synuclein expression in transfected cell lines. In pulse-chase experiments alpha-synuclein appeared to be stable over long periods (t((1)/(2)) 54 h) and no endoproteolytic processing was observed. alpha-Synuclein was constitutively phosphorylated in human kidney 293 cells as well as in rat pheochromocytoma PC12 cells. In both cell lines phosphorylation was highly sensitive to phosphatases, since okadaic acid markedly stabilized phosphate incorporation. Phosphoamino acid analysis revealed that phosphorylation occurred predominantly on serine. Using site-directed mutagenesis we have identified a major phosphorylation site at serine 129 within the C-terminal domain of alpha-synuclein. An additional site, which was phosphorylated less efficiently, was mapped to serine 87. The major phosphorylation site was located within a consensus recognition sequence of casein kinase 1 (CK-1). In vitro experiments and two-dimensional phosphopeptide mapping provided further evidence that serine 129 was phosphorylated by CK-1 and CK-2. Moreover, phosphorylation of serine 129 was reduced in vivo upon inhibition of CK-1 or CK-2. These data demonstrate that alpha-synuclein is constitutively phosphorylated within its C terminus and may indicate that the function of alpha-synuclein is regulated by phosphorylation/dephosphorylation.
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PMID:Constitutive phosphorylation of the Parkinson's disease associated alpha-synuclein. 1061 30

Recent evidence has linked striatal N-methyl-D-aspartate (NMDA) receptor function to the adverse effects of long-term dopaminergic treatment in Parkinson's disease. We have studied the abundance, composition, and phosphorylation of NMDA receptor subunits (NRs) in the rat 6-hydroxydopamine lesion model of parkinsonism. In lesioned striatum, the abundance of NR1 and NR2B in striatal membranes was decreased to 68 +/- 3.2 and 62 +/- 4.4%, respectively, relative to the unlesioned striata, whereas the abundance of NR2A was unchanged. Coimmunoprecipitation of NMDA receptors under nondenaturing conditions revealed that these changes reflected a selective depletion of receptors composed of NR1/NR2B, without alteration in receptors composed of NR1/NR2A. However, the abundance and composition of striatal NMDA receptors in extracts containing both cytoplasmic and membrane proteins were not altered in lesioned rats, suggesting that the changes in the membrane fraction resulted from intracellular redistribution of receptors. The phosphorylation of NR1 protein at serine 890 and serine 896, but not at serine 897, and the tyrosine phosphorylation of NR2B but not NR2A were decreased in the membrane fraction of the lesioned striatum. Chronic treatment of lesioned rats with L-dopa normalized the alterations in the abundance and subunit composition of the NMDA receptors in striatal membranes, and produced striking hyperphosphorylation, both of NR1 at serine residues, and NR2A and NR2B at tyrosine residues. These findings suggest that the adverse motor effects of chronic L-dopa therapy may result from alterations in regulatory phosphorylation sites on NMDA receptors.
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PMID:Alterations in subunit expression, composition, and phosphorylation of striatal N-methyl-D-aspartate glutamate receptors in a rat 6-hydroxydopamine model of Parkinson's disease. 1064 44


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