Results 251 to 260 of about 11,930 (298)

Metabolism of Dihydroxyphenylalanine in Human Subjects

Nature, 1967
THE metabolism of dihydroxyphenylalanine (DOPA; I, R = H) may be very complex. By analogy with other amino-acids, degradation may involve decarboxylation (route A) or transamination (route B), with methylation of the 3-hydroxy group possible at any stage. The principal metabolite in normal human urine appears to be homovanillic acid (HVA; III, R = CH3),
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The influence of imipramine on the central effects of dihydroxyphenylalanine

Neuropharmacology, 1970
Abstract A study was made in animals with chronically implanted electrodes, and in acute experiments, in order to analyze the influence of imipramine (IM) on the EEG effects of dihydroxyphenylalanine (DOPA). The following results have been obtained: 1. (1) IM potentiated the awakening effect of DOPA in reserpinized cats.
K, Kadzielawa, E, Widy
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Clinical experience with dihydroxyphenylalanine (DOPA) in depression

Journal of Psychiatric Research, 1963
THIS is a report of the rGsults of a clinical trial of dihydroxyphenylalanine (DOPA), a precursor of catechol amines, in the treatment of depression. This experiment was undertaken as an indirect test of the catechol amine theory of affective disorders, which proposes that depressed patients have an absolute or relative deficiency of central nervous ...
G L, KLERMAN, J J, SCHILDKRAUT, L L, HASENBUSH, M, GREENBLATT, D G, FRIEND   +4 more
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Electroencephalographic analysis of the central action of dihydroxyphenylalanine

Electroencephalography and Clinical Neurophysiology, 1970
Abstract 1. 1. The EEG effects of DOPA were analysed in cats, depending upon the level of brain-stem section. 2. 2. In contrast with cats with chronically implanted electrodes, gallamine-immobilized, and with encephale isole cats, in which DOPA is unable to induce profound changes in the EEG pattern and behaviour, this amino acid elicits an
K, Kadzielawa, E, Widy-Tyszkiewicz
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Syntheses of α-ethynyl-3, 4-dihydroxyphenylalanine and α-vinyl-3, 4-dihydroxyphenylalanine

Tetrahedron Letters, 1977
3,4-Dihydroxy-benzoesaureester (I) liefert mit Diphenyldichlormethan den cyclischen Ester (II), der nach Reduktion zum Carbinol (IIIa) ein Benzylchlorid (IIIb) gibt, das mit dem Acetylen-imin (IV) zu einem Substitutionsprodukt (V) fuhrt.
D. Taub, A.A. Patchett
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ChemInform Abstract: SYNTHESES OF α‐ETHYNYL‐3,4‐DIHYDROXYPHENYLALANINE AND α‐VINYL‐3,4‐DIHYDROXYPHENYLALANINE

Chemischer Informationsdienst, 1977
Abstract3,4‐Dihydroxy‐benzoesäureester (I) liefert mit Diphenyldichlormethan den cyclischen Ester (II), der nach Reduktion zum Carbinol (IIIa) ein Benzylchlorid (IIIb) gibt, das mit dem Acetylen‐imin (IV) zu einem Substitutionsprodukt (V) führt.
D. TAUB, A. A. PATCHETT
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The Cerebral Metabolism of L-Dihydroxyphenylalanine

Pharmacology, 2008
The regional cerebral distribution of carbon-14 activity was studied using auto-radiography following the intravenous administration of L-3,4-dihydroxyphenyl-(3-14C)-ala-nine (14C-L-dopa) to rats pretreated with carbidopa. 5 min after 14C-L-dopa administration, the regional cerebral distribution of carbon-14 varied with regional cerebral blood flow ...
M.K. Horne, C.H. Cheng, G.F. Wooten
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The action of L‐dihydroxyphenylalanine in patients receiving nialamide

Clinical Pharmacology & Therapeutics, 1965
Nialamide produces effective monamine oxidase inhibition resulting in a three‐ to fivefold increase in tryptamine excretion when administered in a dose of 100 mg. for 10 days. L‐Dihydroxyphenylalanine, given in a dose of 75 to 100 mg. to normal volunteers receiving nialamide in a dose of 100 mg.
D G, FRIEND, W R, BELL, N S, KLINE
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Stability of collagen in the presence of 3,4-dihydroxyphenylalanine (DOPA)

Journal of Photochemistry and Photobiology B: Biology, 2009
Many cross-linking agents for collagen are available with varying levels of toxicity and some are in use in biomedical implants of collagen. L-DOPA (3,4-dihydroxyphenylalanine), a neurotransmitter, is a naturally present compound in the living system and is the target in therapeutic strategy of Parkinson's disease.
R, Usha, A, Rajaram, T, Ramasami
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A method for the determination of 3,4-dihydroxyphenylalanine (DOPA) in brain

Naunyn-Schmiedeberg's Archives of Pharmacology, 1972
The method is an extension of the chromatographic separation procedure for 5-HIAA and 5-HTP published by Lindqvist (1971). Brain tissue is extracted with perchloric acid. After adjustment of the pH to 2 the extract is passed through a Dowex 50W, X-4 column.
W, Kehr, A, Carlsson, M, Lindqvist
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