An alternative route for biosynthesis of norepinephrine

Creveling, Cyrus R.; Levitt, Morton; Undenfriend, Sidney

doi:10.1016/0024-3205(62)90112-1

Cited by 44 publications

(3 citation statements)

References 11 publications

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“…It is known that the enzymes involved in catecholamine synthesis can utilize a variety of substrates (Axelrod, 1962;Bridgers and Kaufman, 1962;Lovenberg et al, 1962). As a result, minor pathways for catecholamine synthesis have been proposed (Creveling et al, 1962;Axelrod, 1963) that involve an alternative enzyme to TH, namely, a mixed function oxidase (MFO), which has been detected in liver homogenates (Axelrod, 1963). The remaining enzymes in the synthetic routes described below (Fig.…”

Section: Discussionmentioning

confidence: 99%

Abundance in the Embryonic Brainstem of Adrenaline During the Absence of Detectable Tyrosine Hydroxylase Activity

Foster

Sundström

Helmer-Matyjek

et al. 1987

Journal of Neurochemistry

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The activities of the catecholamine synthetic enzymes tyrosine hydroxylase and phenylethanolamine N-methyltransferase, and the concentrations of the catecholamines and their respective metabolites, have been measured in the dorsal and ventral halves of the brainstem at various ages in the embryonic and adult rat. The activity of phenylethanolamine N-methyltransferase in both parts of the brainstem at day 14 of gestation is at or greater than adult levels and thereafter displays relatively small variations during ontogeny. Tyrosine hydroxylase activity, in contrast, is undetectable at day 14 and increases slowly, achieving only 20-25% of adult values by day 18 of gestation. Adrenaline concentrations correlate well with the activity of phenylethanolamine N-methyltransferase, showing a precocious development, whereas noradrenaline and 3,4-dihydroxyphenylethylamine (dopamine) concentrations are more closely related to the enhancement of tyrosine hydroxylase activity; at day 18 of gestation, for example, they are only 5 and 10%, respectively, of the adult values. The concentrations of the metabolites of noradrenaline and dopamine are suggestive of a high rate of turnover. These results confirm previous immunocytochemical evidence of a tardy appearance of tyrosine hydroxylase-like immunoreactivity in the phenylethanolamine N-methyltransferase-positive perikarya of the embryonic medulla oblongata. In addition, the abundance of adrenaline in this area at early gestational stages strongly suggests that, despite the paucity of tyrosine hydroxylase, phenylethanolamine N-methyltransferase is active in vivo and is utilizing a substrate other than noradrenaline. It is likely, however, that at later stages of gestation, when tyrosine hydroxylase is present at sufficient activity to supply noradrenaline, the conventional synthetic pathway for adrenaline formation comes into being.

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Section: Discussionmentioning

confidence: 99%

Abundance in the Embryonic Brainstem of Adrenaline During the Absence of Detectable Tyrosine Hydroxylase Activity

Foster

Sundström

Helmer-Matyjek

et al. 1987

Journal of Neurochemistry

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“…sulted in the excretion of trace amounts of noradrenaline and larger amounts of normetanephrine and metanephrine (2). Thus there may be many alter?…”

Section: Most Of the Enzymes Involvedmentioning

confidence: 99%

Enzymatic Formation of Adrenaline and Other Catechols from Monophenols

Axelrod

1963

Science

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An enzyme that forms adrenaline from p- and m-sympathol and dopamine from p- and m-tyramine is localized in the microsomes of rabbit liver and requires the reduced form of nicotinamide adenine dinucleotide phosphate. The enzyme is nonspecific and can form catechols from the following normally occurring and foreign phenols: p- and m-octopamine, p-hydroxyephedrine, phenol, stilbestrol, N-acetyl-p-aminophenol, estradiol and N-acetylserotonin.

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“…A tyramine hydroxylase is required to produce dopamine from tyramine. Tyramine hydroxylation has been demonstrated in vitro (1) and in vivo ( 5 ) .…”

Section: Tyrosine Decarboxylase or L-aromatic Amino Acid Decarboxylasementioning

confidence: 99%

Production of Melanin Precursors By A Mutant of Tetrahymena Thermophila*

Kaney

Knox

1980

The Journal of Protozoology

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A mutant of Tetrahymena thermophila, "pig," excretes melanin precursors into the culture medium where spontaneous polymerization to melanin occurs. The precursors, probably oxidation products of catecholamines, are produced in large amounts by the mutant by decarboxylation of tyrosine and hydroxylation of the resulting tyramine. Overproduction and excretion of precursors by the mutant appears to result from elevated specific activity of L-aromatic amino acid decarboxylase (DOPA decarboxylase) (E.C. 4.1.1.26).

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An alternative route for biosynthesis of norepinephrine

Cited by 44 publications

References 11 publications

Abundance in the Embryonic Brainstem of Adrenaline During the Absence of Detectable Tyrosine Hydroxylase Activity

Abundance in the Embryonic Brainstem of Adrenaline During the Absence of Detectable Tyrosine Hydroxylase Activity

Enzymatic Formation of Adrenaline and Other Catechols from Monophenols

Production of Melanin Precursors By A Mutant of Tetrahymena Thermophila*

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