Results 321 to 330 of about 24,273 (376)

Dihydroxyphenylalanine secretion in a malignant pheochromocytoma

The American Journal of Medicine, 1967
Abstract Studies on catecholamine metabolism in patients with neural crest tumors revealed a high plasma level of 3,4-dihydroxyphenylalanine (dopa) and dopamine (DM) in association with a malignant, but not a benign pheochromocytoma. The large amounts of these amines may have been mistaken in other studies for norepinephrine because of the use of a ...
A.H. Anton, C.M. Williams, D.F. Sayre, M. Greer   +3 more
openaire   +3 more sources

Decarboxylation of 3,4-dihydroxyphenylalanine by oxyhemoglobin

Biochemical and Biophysical Research Communications, 1972
Abstract A lysate of red blood cells catalyzes the decarboxylation of 3,4-dihydroxyphenylalanine. This activity appears to be due to a reaction with oxyhemoglobin and not the presence of aromatic L amino acid decarboxylase in erythrocytes.
Hirohiko Yamabe, Walter Lovenberg
openaire   +3 more sources

Self-Powered Enzymatic Electrosynthesis of l-3,4-Dihydroxyphenylalanine in a Hybrid Bioelectrochemical System

ACS Sustainable Chemistry and Engineering, 2018
Enzymatic electrosynthesis has been used to synthesize a variety of chemicals with the electric energy input.
R. Wu, Zhiguang Zhu
semanticscholar   +1 more source

Origin and Significance of Plasma Dihydroxyphenylalanine

1997
Publisher Summary This chapter summarizes the origin and the significance of plasma 3,4-Dihydroxyphenylalanine (DOPA). DOPA is both a catecholamine and an aromatic amino acid. DOPA occupies a central position in the function of the sympathetic nervous system. It is the immediate product of the rate-limiting step in the biosynthesis of catecholamines:
Eldrup, Ebbe, Richter, Erik A., Hetland, Merete L., Andreasen, Jan, Hilsted, Jannik, Møller, Svend E., Christensen, Niels Juel   +6 more
openaire   +3 more sources

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 ...
Q L. Lee Hasenbush, Joseph J. Schildkraut, Gerald L. Klerman, Milton Greenblatt, Dale G. Friend   +4 more
openaire   +3 more sources

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.
E. Widy, K. Ka̧dzielawa
openaire   +3 more sources

Self-assembly of l -cysteine–gold nanoparticles as chiral probes for visual recognition of 3,4-dihydroxyphenylalanine enantiomers

, 2015
A simple protocol to distinguish enantiomers is extremely intriguing and useful. Herein, we report on a method for the visual recognition of 3,4-dihydroxyphenylalanine (Dopa) enantiomers.
Lin Zhang, Chunli Xu, Guoxin Song, Baoxin Li   +3 more
semanticscholar   +1 more source

A novel electrochemical chiral sensor for 3,4-dihydroxyphenylalanine based on the combination of single-walled carbon nanotubes, sulfuric acid and square wave voltammetry.

In Analysis, 2014
We demonstrate, for the first time, an electrochemical sensor that provides antipodal signals upon application of square wave voltammetry (SWV), for enantioselective recognition of 3,4-dihydroxyphenylalanine based on chiral single-walled carbon nanotubes
Lisha Chen, F. Chang, Lingchen Meng, Meixian Li, Zhiwei Zhu   +4 more
semanticscholar   +1 more source

Novel chiral PEDOTs for selective recognition of 3,4‐dihydroxyphenylalanine enantiomers: Synthesis and characterization

, 2015
Two new 3,4-ethylenedioxythiophene (EDOT) derivatives, (2R)-(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methyl 2-phenylpropanoate ((R)-EDTM-PP) and (2S)-(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methyl 2-phenylpropanoate ((S)-EDTM-PP), were synthesized and
Liqi Dong, Baoyang Lu, X. Duan, Jingkun Xu, D. Hu, Kai-xin Zhang, Xiao-fei Zhu, Hui Sun, Shouli Ming, Zhipeng Wang, Shijie Zhen   +10 more
semanticscholar   +1 more source

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.
David Taub, Arthur A. Patchett
openaire   +2 more sources