Biosynthesis of Cerebral Phenolic Amines. I. In Vivo Formation of p-Tyramine, Octopamine, and Synephrine

1972 ◽  
Vol 50 (3) ◽  
pp. 261-267 ◽  
Author(s):  
Alan A. Boulton ◽  
P. H. Wu
Keyword(s):  
Monoamine Oxidase ◽  
Monoamine Oxidase Inhibitor ◽  
Oxidase Inhibitor ◽  
Intraventricular Injection

Following the intraventricular injection of 14C-labelled dopamine, p-tyrosine, and p-tyramine to rats pretreated with a monoamine oxidase inhibitor, the labelled phenolic amines p-tyramine, octopamine, and synephrine were isolated and identified as their DNS derivatives. Differences in the amounts of the phenolicamines formed suggest that mechanisms other than just decarboxylation are involved.

scholarly journals 4-Aminobutyrate in mammalian putrescine catabolism

1975 ◽  
Vol 152 (2) ◽  
pp. 201-210 ◽  
Author(s):  
N. Seiler ◽  
B. Eichentopf
Keyword(s):  
Monoamine Oxidase ◽  
Diamine Oxidase ◽  
Monoamine Oxidase Inhibitor ◽  
Mitochondrial Pathway ◽  
Oxidase Inhibitor ◽  
Catabolic Pathway ◽  
Oxidative Deamination ◽  
Aminobutyrate Aminotransferase ◽  
Derivatives Of

The effects of inhibitors of diamine oxidase (EC 1.4.3.6), monoamine oxidase (EC 1.4.3.4) and 4-aminobutyrate aminotransferase (EC 2.6.1.19) on the catabolism of putrescine in mice in vivo were studied. Diamine oxidase inhibitors and carboxymethoxylamine (amino-oxyacetate) markedly inhibit the metabolism of [14C]putrescine to 14CO2, but affect different enzymes. Aminoguanidine specifically inhibits the mitochondrial and non-mitochondrial diamine oxidases, whereas carboxymethoxylamine specifically inhibits 4-aminobutyrate transamination by the mitochondrial pathway. Hydrazine inhibits at both sites, and results in increased concentrations of 4-aminobutyrate in brain and liver. Pretreatment of mice with carboxymethoxylamine and [14C]putrescine leads to the urinary excretion of amino[14C]butyrate. Carboxymethoxylamine does not affect the non-mitochondrial pathway of putrescine catabolism, as the product of oxidative deamination of putrescine in the extramitochondrial compartment is not further oxidized but is excreted in the urine as derivatives of 4-aminobutyraldehyde. Another catabolic pathway of putrescine involves monoamine oxidase, and the monoamine oxidase inhibitor, pargyline, decreases the metabolism of [14C]putrescine to 14CO2in vivo. Catabolism of putrescine to CO2in vivo occurs along different pathways, both of which have 4-aminobutyrate as a common intermediate, in contrast with the non-mitochondrial catabolism of putrescine, which terminates in the excretion of 4-aminobutyraldehyde derivatives. The significance of the different pathways is discussed.

Urinary Catecholamine Metabolite and Tribulin Output During Lactate Infusion

1988 ◽  
Vol 152 (1) ◽  
pp. 122-126 ◽  
Author(s):  
Angela Clow ◽  
Vivette Glover ◽  
M. W. Weg ◽  
P. L. Walker ◽  
D. V. Sheehan ◽  
...  
Keyword(s):  
Monoamine Oxidase ◽  
Homovanillic Acid ◽  
Monoamine Oxidase Inhibitor ◽  
Benzodiazepine Receptor ◽  
Oxidase Inhibitor ◽  
Panic Attacks ◽  
Urinary Catecholamine ◽  
Lactate Infusion ◽  
Normal Controls

Urinary output of homovanillic acid and 4-hydroxy-3-methoxymandelic acid was decreased both in patients with panic attacks and in normal controls during lactate infusion, whereas that of tribulin (an endogenous monoamine oxidase inhibitor and benzodiazepine receptor binding inhibitor) was increased. There was no change in urinary excretion of any of these compounds during saline infusion. These findings provide further evidence of a link between tribulin output and stress and anxiety in man and point to its possible in vivo action as a monoamine oxidase inhibitor.

scholarly journals The inhibitory action of l-dihydroxyphenylalanine (l-dopa) in the presence of a monoamine oxidase inhibitor on protein synthesis in vivo and the partial amelioration of this by methionine supplementation

1980 ◽  
Vol 192 (2) ◽  
pp. 703-707 ◽  
Author(s):  
A H Bone ◽  
H R Taufek
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Monoamine Oxidase ◽  
Inhibitory Action ◽  
Monoamine Oxidase Inhibitor ◽  
Age Groups ◽  
Specific Radioactivity ◽  
Oxidase Inhibitor ◽  
Inhibitor Treatment

Male Wistar rats of various age groups were injected daily over a period of 3 weeks with iproniazid (10 micrograms/g body wt.) and L-dihydroxyphenylalanine (L-dopa; 0.1 mg/g body wt.). On the final day 1 h before the termination of the experiment the animals were injected with L-[14C]valine (0.1 microCi/g body wt.). The specific radioactivity of the valine in the proteins of the subcellular fractions of the tissues examined, relative to the time-integrated mean specific radioactivity of this amino acid in the acid-soluble pools of these tissues, was used to assess protein synthesis. The L-dopa/monoamine oxidase-inhibitor treatment was associated with 30–40% inhibition of protein synthesis. Supplementation of the dietary methionine intake by injection of this amino acid markedly diminished the inhibitory action of the L-dopa/monoamine oxidase-inhibitor treatment on protein synthesis in all fractions examined.

Day–night rhythm of 5-methoxytryptamine biosynthesis in the pineal gland of the golden hamster (Mesocricetus auratus)

1988 ◽  
Vol 118 (3) ◽  
pp. 389-397 ◽  
Author(s):  
A. M. Galzin ◽  
M. T. Eon ◽  
H. Esnaud ◽  
C. R. Lee ◽  
P. Pévet ◽  
...  
Keyword(s):  
Monoamine Oxidase ◽  
Pineal Gland ◽  
Monoamine Oxidase Inhibitor ◽  
Mesocricetus Auratus ◽  
Oxidase Inhibitor ◽  
Serotonin Release ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Method ◽  
Liquid Chromatography Method

ABSTRACT 5-Methoxytryptamine is a potent agonist of presynaptic 5-hydroxytryptamine autoreceptors modulating serotonin release in the central nervous system. This methoxyindole can be synthesized in the pineal gland, but its presence in vivo is still controversial, probably because of rapid catabolism by monoamine oxidase. An improved high-pressure liquid chromatography method, with coulometric detection, has been developed for the simultaneous measurement of melatonin, 5-methoxytryptamine, 5-methoxytryptophol and 5-methoxyindolacetic acid. We have demonstrated a day–night rhythmicity in the amount of 5-methoxytryptamine in the pineal gland of golden hamsters (Mesocricetus auratus) maintained under a long photoperiod (14 h light: 10 h darkness) and pretreated with the monoamine oxidase inhibitor pargyline. Levels of 5-methoxytryptamine were highest at 16.30 h and lowest at 00.30 h. The rhythm for 5-methoxytryptamine appears to be the same as for serotonin (opposite in phase to that of melatonin). The identification of 5-methoxytryptamine has been confirmed by analysis with gas chromatography–mass spectrometry. J. Endocr. (1988) 118, 389–397

Sign in / Sign up

Export Citation Format

Share Document