In vivo studies on the effect of monoamine oxidase inhibitors on dopamine and serotonin metabolism in rat brain areas

1990 ◽  
pp. 85-88
Author(s):  
H.-W. Clement ◽  
Chr. Grote ◽  
W. Wesemann
Keyword(s):  
Monoamine Oxidase ◽  
Rat Brain ◽  
Monoamine Oxidase Inhibitors ◽  
In Vivo Studies ◽  
Serotonin Metabolism ◽  
Brain Areas

In vivo studies on the conversion of m-tyrosine to 3,4-dihydroxyphenylalanine in the rat

1977 ◽  
Vol 55 (10) ◽  
pp. 1103-1107 ◽  
Author(s):  
J. H. Tong ◽  
R. G. Smyth ◽  
N. L. Benoiton ◽  
A. D'Iorio
Keyword(s):  
Rat Brain ◽  
Enzyme Inhibitors ◽  
Phenylalanine Hydroxylase ◽  
Intraperitoneal Administration ◽  
In Vivo Studies ◽  
Dopa Decarboxylase ◽  
Decarboxylase Inhibitor ◽  
Specific Enzyme ◽  
Dihydroxyphenylacetic Acid

The question whether m-tyrosine can give rise to catechols in vivo has been investigated using labelled precursor. DL-[2-l4C]m-tyrosine (38 μCi/mmol (1 Ci = 37 GBq)) was synthesized from [2-14C]glycine. Radioactive catechols in rat brain, liver, and kidneys were examined 15 min after intraperitoneal administration of DL-[2-14C]m-tyrosine (100 mg/kg). The kidney was the only organ which showed demonstrable amounts of radioactive catechols, and about 14% of the catechols formed was identified as 3,4-dihydroxyphenylalanine (dopa), 22% as 3,4-dihydroxyphenylacetic acid, and 56% as dopamine. However, when the animals were pretreated with dopa decarboxylase inhibitor, labelled catechols were also observed in liver and brain, and dopa accounted for over 95% of the catechols formed in all three organs examined. Thus it is clear that m-tyrosine can be hydroxylated in vivo. Results from experiments using [2-14C]m-tyrosine enantiomers and specific enzyme inhibitors suggest that phenylalanine hydroxylase could be the enzyme catalyzing this reaction.

scholarly journals Phenethylamines in brain and liver of rats with experimentally induced phenylketonuria-like characteristics

1973 ◽  
Vol 132 (1) ◽  
pp. 95-100 ◽  
Author(s):  
David J. Edwards ◽  
Karl Blau
Keyword(s):  
Monoamine Oxidase ◽  
Rat Brain ◽  
Phenylalanine Hydroxylase ◽  
Brain Regions ◽  
Subcellular Fractions ◽  
Brain Cells ◽  
Blood Phenylalanine ◽  
Low Concentrations ◽  
Experimentally Induced

1. Phenethylamines were extracted from brain and liver of rats with phenylketonuria-like characteristics produced in vivo by inhibition of phenylalanine hydroxylase (EC 1.14.3.1) with p-chlorophenylalanine, with or without phenylalanine administration. To protect amines against oxidation by monoamine oxidase, pargyline was also administered. 2. β-Phenethylamine was the major compound found in brain and liver. β-Phenethanolamine and octopamine were also present, in lesser amounts, and the concentrations of these three amines paralleled blood phenylalanine concentrations. By comparison, tissues from control animals had only very low concentrations of these amines. 3. Small amounts of normetadrenaline, m-tyramine and 3-methoxytyramine were also found. 4. The inhibitors used, p-chlorophenylalanine and pargyline, gave rise to p-chlorophenethylamine and benzylamine respectively, the first via decarboxylation, the second probably by breakdown during extraction. 5. Distribution of phenethylamines in different brain regions and in subcellular fractions of rat brain cells was also investigated. The content of phenethylamine was highest in the striatum. 6. These findings are discussed in the light of changes occurring in human patients with uncontrolled phenylketonuria.

Interaction of β-casomorphins with multiple opioid receptors: In vitro and in vivo studies in the newborn rat brain

1986 ◽  
Vol 30 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Andrea Volterra ◽  
Patrizia Restani ◽  
Nicoletta Brunello ◽  
Corrado L. Galli ◽  
Giorgio Racagni
Keyword(s):  
Rat Brain ◽  
Opioid Receptors ◽  
In Vivo Studies ◽  
Newborn Rat

11C-harmine as a tracer for monoamine oxidase a (MAO-A): In vitro and in vivo studies

1997 ◽  
Vol 24 (4) ◽  
pp. 287-293 ◽  
Author(s):  
Mats Bergström ◽  
Göran Westerberg ◽  
Bengt Långström
Keyword(s):  
Monoamine Oxidase ◽  
Monoamine Oxidase A ◽  
In Vivo Studies ◽  
Mao A
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