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L-Amino acid decarboxylase

Together with dopamine, adrenaline and noradrenaline belong to the endogenous catecholamines that are synthesized from the precursor amino acid tyrosine (Fig. 1). In the first biosynthetic step, tyrosine hydroxylase generates l-DOPA which is further converted to dopamine by the aromatic L-amino acid decarboxylase ( Dopa decarboxylase). Dopamine is transported from the cytosol into synaptic vesicles by a vesicular monoamine transporter. In sympathetic nerves, vesicular dopamine (3-hydroxylase generates the neurotransmitter noradrenaline. In chromaffin cells of the adrenal medulla, approximately 80% of the noradrenaline is further converted into adrenaline by the enzyme phenylethanolamine-A-methyltransferase. [Pg.42]

EP 436 252 (AKZO appl. 19.12.1990 NL-prior. 30.12.1989). combination with L-amino acid decarboxylase inhibitors ... [Pg.1344]

Decarboxylation of histidine to histamine is catalyzed by a broad-specificity aromatic L-amino acid decarboxylase that also catalyzes the decarboxylation of dopa, 5-hy-droxytryptophan, phenylalanine, tyrosine, and tryptophan. a-Methyl amino acids, which inhibit decarboxylase activity, find appfication as antihypertensive agents. Histidine compounds present in the human body include ergothioneine, carnosine, and dietary anserine (Figure 31-2). Urinary levels of 3-methylhistidine are unusually low in patients with Wilson s disease. [Pg.265]

Histamine is synthesised by decarboxylation of histidine, its amino-acid precursor, by the specific enzyme histidine decarboxylase, which like glutaminic acid decarboxylase requires pyridoxal phosphate as co-factor. Histidine is a poor substrate for the L-amino-acid decarboxylase responsible for DA and NA synthesis. The synthesis of histamine in the brain can be increased by the administration of histidine, so its decarboxylase is presumably not saturated normally, but it can be inhibited by a fluoromethylhistidine. No high-affinity neuronal uptake has been demonstrated for histamine although after initial metabolism by histamine A-methyl transferase to 3-methylhistamine, it is deaminated by intraneuronal MAOb to 3-methylimidazole acetic acid (Fig. 13.4). A Ca +-dependent KCl-induced release of histamine has been demonstrated by microdialysis in the rat hypothalamus (Russell et al. 1990) but its overflow in some areas, such as the striatum, is neither increased by KCl nor reduced by tetradotoxin and probably comes from mast cells. [Pg.270]

Figure 13.7 Synthesis and structure of the trace amines phenylethylamine, /)-tyramine and tryptamine. These are all formed by decarboxylation rather than hydroxylation of the precursors of the established monoamine neurotransmitters, dopamine and 5-HT. (1) Decarboxylation by aromatic L-amino acid decarboxylase (2) phenylaline hydroxylase (3) tyrosine hydroxylase (4) tryptophan hydroxylase... Figure 13.7 Synthesis and structure of the trace amines phenylethylamine, /)-tyramine and tryptamine. These are all formed by decarboxylation rather than hydroxylation of the precursors of the established monoamine neurotransmitters, dopamine and 5-HT. (1) Decarboxylation by aromatic L-amino acid decarboxylase (2) phenylaline hydroxylase (3) tyrosine hydroxylase (4) tryptophan hydroxylase...
Albert, V. R., Allen, J. M., and Joh, T. H. (1987). A single gene codes for aromatic L-amino acid decarboxylase in both neuronal and non-neuronal tissues. J. Biol. Chem. 262 9404-9411. [Pg.82]

Ichinose, H., Kurosawa, Y., Titani, K., Fujita, K., and Nagatsu, T. (1989). Isolation and characterization of a cDNA clone encoding human aromatic L-amino acid decarboxylase. Biochem. Biophys. Res. Commun. 164 1024-1030. [Pg.84]

Jaeger, C. B., Teitelman, G Joh, T. H., Albert, V. R Park, D. H., and Reis, D. J. (1983). Some neurons of the rat central nervous system contain aromatic L-amino acid decarboxylase but not monoamines. Science 219 1233-1235. [Pg.84]

Kang, U. J and Joh, T. H. (1990). Deduced amino acid sequence of bovine L-amino acid decarboxylase homology to other decarboxylases. Mol. Brain Res. 8 83-87. [Pg.85]

Lovenberg, W Weissbach, W., and Udenfriend, S. (1962). Aromatic L-amino acid decarboxylase. J. Biol. Chem. 237 89-93. [Pg.85]

Nagatsu, T., Ichinose, H., Kojima, K., Kameya, T., Shimase, J., Kodama, T., and Shimosato, U. (1985). Aromatic L-amino acid decarboxylase activities in human lung tissues comparison between normal lung and lung carcinomas. Biochem. Med. 34 52-59. [Pg.85]

Rahman, M. K Nagatsu, T., and Kato, T. (1981). Aromatic L-amino acid decarboxylase activity in central and peripheral tissues and serum of rats with L-DOPA and L-5-hydroxytryptophan as substrates. Biochem. Pharmacol. 30 645-649. [Pg.86]

Thai, A. L. V., Coste, E., Allen, J. M., Palmiter, R. D., and Weber, M. J. (1993). Identification of a neuron-specific promoter of human aromatic L-amino acid decarboxylase gene. Mol. Brain. Res 17 227-238. [Pg.86]

L-dopa is effective in the treatment of Parkinson s disease, a disorder characterised by low levels of dopamine, since L-dopa is metabolised into dopamine. However, this biosynthesis normally occurs in both the peripheral nervous system (PNS) and the central nervous system CNS. The related drug carbidopa inhibits aromatic L-amino acid decarboxylase only in the periphery, since it does not cross the blood-brain barrier. So, when carbidopa is given with L-dopa, it reduces the biosynthesis of L-dopa to dopamine in the periphery and, thus, increases the bioavailability of L-dopa for the dopaminergic neurons in the brain. Hence, carbidopa increases the clinical efficacy of L-dopa for Parkinsonian patients. [Pg.33]

Carbidopa An inhibitor of aromatic L-amino acid decarboxylase used with L-dopa in the treatment of Parkinson s disease. [Pg.239]

The answer is c. (idardman, p 510.) Carbidopa is an inhibitor of aromatic L-amino acid decarboxylase. It cannot readily penetrate the central nervous system (CNS) and, thus, decreases the decarboxylation of L-clopa in the peripheral tissues. This promotes an increased concentration of L-clopa in the nigrostriatum, where it is converted to dopamine. In addition, the effective dose of L-dopa can be reduced... [Pg.156]

The other enzyme involved in the synthesis of 5-HT, aromatic L-amino acid decarboxylase (AADC) (EC 4.1.1.28), is a soluble pyridoxal-5 -phosphate-dependent enzyme, which converts 5-HTP to 5-HT (Fig. 13-5). It has been demonstrated that administration of pyridoxine increases the rate of synthesis of 5-HT in monkey brain, as revealed using position emission tomography (this technique is discussed in Ch. 58). This presumably reflects a regulatory effect of pyridoxine on AADC activity and raises the interesting issue of the use of pyridoxine supplementation in situations associated with 5-HT deficiency. [Pg.231]

Eaton, M. J., Gudehithlu, K. P., Quach, T., Sivia, C. P., Hadjiconstantinou, M. and Neff, N. H. Distribution of aromatic L-amino acid decarboxylase mRNA in mouse brain by in situ hybridization histology. J. Comp. Neurol. 337 640-654,1993. [Pg.247]

AADC aromatic L-amino acid decarboxylase BDZ benzodiazepine... [Pg.963]

In the CNS and elsewhere, L-dopa is converted by L-amino acid decarboxylase (L-AAD) to dopamine. In the periphery, L-AAD can be blocked by administering carbidopa or benserazide, which does not cross the blood-... [Pg.645]

A group of enzymes which may be employed in the measurement of L amino acids are the L-amino acid decarboxylases (EC 4.1.1) of bacterial origin, many of which are substrate specific. They catalyse reactions of the type ... [Pg.365]

These strategies are aimed at either cytosolic enzymes, such as L-amino acid decarboxylase, 3-lyase and N-acetyl transferase, or enzymes that are expressed at the brush border of the proximal tubule and to a lesser extent on the basolateral membrane, such as y-glutamyl transpeptidase (GGT). [Pg.132]

Synthesis of norepinephrine begins with the amino acid tyrosine, which enters the neuron by active transport, perhaps facilitated by a permease. In the neuronal cytosol, tyrosine is converted by the enzyme tyrosine hydroxylase to dihydroxyphenylalanine (dopa), which is converted to dopamine by the enzyme aromatic L-amino acid decarboxylase, sometimes termed dopa-decarboxylase. The dopamine is actively transported into storage vesicles, where it is converted to norepinephrine (the transmitter) by dopamine (3-hydroxylase, an enzyme within the storage vesicle. [Pg.90]

M.G. Palfreyman, I.A. McDonald, J.R. Fozard, Y. Mely, A.J. Sleight, M. Zreika, J. Wagner, P. Bey, P.J. Lewis, Inhibition of monoamine oxidase selectively in brain monoamine nerves using the bioprecursor (MDL 72394), a substrate for aromatic L-amino acid decarboxylase, J. Neurochem. 45 (1985) 1850-1860. [Pg.692]

J. R. Fozard (1982). Highly potent irreversible inhibitors of aromatic L-amino acid decarboxylase. Trends Pharmacol. Sci. 3 429. [Pg.303]

It is an indole ethylamine formed in biological systems from the amino acid L-tryptophan by hydroxylation with tryptophan hydroxylase enzyme, followed by the decarboxylation by the nonspecific aromatic L-amino acid decarboxylase. 5-HT is then taken up into secretory granules and stored. [Pg.221]

Shen H, Kannari K, Yamato H, et al. Effects of benser-azide on L-DOPA-derived extracellular dopamine levels and aromatic L-amino acid decarboxylase activity in the striatum of 6-hydroxydopamine-lesioned rats. Tohoku J Exp Med. 2003 199 149-159. [Pg.133]


See other pages where L-Amino acid decarboxylase is mentioned: [Pg.19]    [Pg.43]    [Pg.162]    [Pg.165]    [Pg.1120]    [Pg.1170]    [Pg.1173]    [Pg.82]    [Pg.84]    [Pg.353]    [Pg.427]    [Pg.165]    [Pg.169]    [Pg.97]    [Pg.283]    [Pg.116]    [Pg.912]    [Pg.576]   
See also in sourсe #XX -- [ Pg.45 ]




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Amino acid decarboxylase

Aromatic L-amino acid decarboxylase

Aromatic L-amino acid decarboxylase AADC)

Dopa Decarboxylase (L-Aromatic Amino Acid

L amino acids

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