THE DISTRIBUTION AND PROPERTIES OF THE NONSPECIFIC N‐METHYLTRANSFERASE IN BRAIN

@article{Saavedra1973THEDA,
  title={THE DISTRIBUTION AND PROPERTIES OF THE NONSPECIFIC N‐METHYLTRANSFERASE IN BRAIN},
  author={Juan M. Saavedra and Joseph T. Coyle and Julius Axelrod},
  journal={Journal of Neurochemistry},
  year={1973},
  volume={20}
}
Abstract— The distribution and properties of a nonspecific N‐methyltransferase in the rat brain are described. The enzyme N‐methylates tryptamine and N‐methyltryptamine as well as β‐phenylethylamine, phenylethanolamine, tyramine and octopamine. The enzyme exhibits a pH optimum of 7·9 with phosphate buffer and has a Km for tryptamine of 28 μM. There are potent inhibitors to the enzyme that can be removed by dialysis. Enzymatic activity is present in the brains of a number of species including… Expand
Multiple N-methyltransferases for aromatic alkylamines in brain.
TLDR
Assays in the presence of each donor in combination with each substrate suggested the possible existence of multiple N-methyltransferases, with one specific for tryptamine and the others non-specific for aromatic alkylamines. Expand
Some properties of phenylethanolamine-N-methyltransferase of rat brain
TLDR
Kinetic studies showed that the type of inhibition of PNMT from rat brain and rat adrenals by SK&F 7698 was the same as described for PnMT from rabbit adrenals. Expand
Tryptamine-N-methyltransferase activity in brain tissue: a re-examination
TLDR
Results which cast some doubt on the existence of a SAM-dependent indole-N-methyltransferase in brain are reported, which is a significant factor in the pathogenesis of some forms of psychotic illness in man. Expand
Characterization of Brain β-Carboline-2-N-Methyltransferase, An Enzyme That May Play a Role in Idiopathic Parkinson's Disease
TLDR
This report describes experiments undertaken to optimize assay conditions for bovine brain β-carboline-2-N-methyltransferase activity, which results in the formation of neurotoxic N-methylated β- carbolinium compounds that may contribute to the development of idiopathic Parkinson's disease. Expand
Studies on the characterization and inhibition of rat brain phenylethanolamine N-methyltransferase
SummaryThe existence of phenylethanolamine N-methyltransferase (PNMT) activity in the rat brain and spinal cord was confirmed using both substrate specificity and selective inhibitors of the adrenalExpand
Distribution of adrenaline-synthesizing enzyme activity in the human brain
TLDR
The distribution of PNMT activity in normal human brain was found to be similar to that in the rat, but, in addition, important activity was found in the substantia nigra, internal pallidium and nucleus accumbens. Expand
Localisation of phenylethanolamine N-methyl transferase in the rat brain nuclei
TLDR
The findings suggest that adrenaline may serve as a neurotransmitter in the central nervous system, and the distribution of the enzyme in specific nuclei of the rat brain is studied. Expand
Distribution and Properties of Thiol S‐Methyltransferase in Rat Brain
TLDR
TMT was found to be unevenly distributed amongst various brain regions, with highest activities in the medulla oblongata and the hippocampus, and with increasing polarity of thiol substrates there was a decrease in the maximal velocities of reaction and an increase in the apparent Km values. Expand
Rabbit Lung Indolethylamine N-Methyltransferase
TLDR
Cloning and expression of a rabbit lung INMT cDNA and cloning of the rabbit INMT gene represent important steps toward determination of the function and regulation of this mammalian methyltransferase enzyme. Expand
Activity of dopamine-beta-hydroxylase (DBH) and phenylethanolamine-N-methyl transferase (PNMT) in heart, lung and chromaffin tissue from the Florida spotted gar Lepisosteus platyrhincus (Holostei).
TLDR
The presence of PNMT in the adrenergically innervated tissues puts Lepisosteus with the teleosts and the amphibians among vertebrates with capacity for truly adrenergic, as opposed to noradrenergic, transmission. Expand
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 18 REFERENCES
The enzymatic N-methylation of serotonin and other amines.
  • J. Axelrod
  • Chemistry, Medicine
  • The Journal of pharmacology and experimental therapeutics
  • 1962
TLDR
The serotonin methylating enzyme can N-methylate a variety of normally occurring compounds such as dopamine, normetanephrine, metanephine, epinephrine, tyramine, and octopamine as well as a varietyof foreign compounds suchAs ephedrine, amphetamine, aniline, normorphine,normeperidine and nornicotine. Expand
Indole(ethyl)amine N-methyltransferase in human brain.
TLDR
Preliminary evidence gathered in laboratories from rats infused intraventricularly with bufotenin has suggested that this substance is at least as potent as its powerfully hallucinogenic 5-methoxy congener, and may not easily cross the blood-brain barrier. Expand
Psychotomimetic N-Methylated Tryptamines: Formation in Brain in vivo and in vitro
TLDR
An enzyme that converts tryptamine and N-methyl-tryptamine to N- methyl-and dimethyltryptamine was found to be present in rat and human brain. Expand
Enzymatic conversion of norepinephrine to epinephrine by the brain.
The epinephrine-forming enzyme phenylethanolamine-N-methyl transferase (PNMT) can be demonstrated in various brain regions of the rat, cat, hen and turtle. The activity of the enzyme is greatest whenExpand
Indole(ethyl)amine N-Methyltransferase in the Brain
An enzyme which N-methylates various indole(ethyl)amine substrates was isolated from brain, separated from the pituitary and the pineal glands. It appeared localized in the supernatant andExpand
Methylation of desmethylimipramine by rabbit lung in vitro.
Abstract Studies of the methylation of analogs of imipramine by N-methyltransferase are described. Desmethylimipramine and nortriptyline, both secondary amines, are rapidly methylated by an enzyme inExpand
REGIONAL STUDIES OF CATECHOLAMINES IN THE RAT BRAIN‐I
TLDR
It is revealed that norepinephrine and dopamine are specifically localized in complex systems of neurons in the brain, a finding which lends support to the hypothesis that both amines may be neurotransmitters in the central nervous system. Expand
Brain levels of tryptamine
TLDR
It is suggested that tryptamine may be a naturally occurring hallucinogen that may play a role both in normal and pathologic functioning of the brain. Expand
Enzymatic Formation of Psychotomimetic Metabolites from Normally Occurring Compounds
An enzyme has been found that N-methylates serotonin and tryptamine to psychotomimetic metabolites, bufotenine and N,N-dimethyltryptamine. This enzyme is highly localized in the rabbit lung and alsoExpand
Enzymatic Synthesis of Adrenaline in Mammalian Brain
TLDR
It is found that adrenaline is synthesized in the brain through the uptake, metabolism and synthesis of adrenaline by mammalian brain. Expand
...
1
2
...