scholarly journals The conjugation of tyramine with sulphate by liver and intestine of different animals

1976 ◽  
Vol 160 (3) ◽  
pp. 491-493 ◽  
Author(s):  
K P Wong
Keyword(s):  
Monoamine Oxidase ◽  
Guinea Pig ◽  
Enzyme Preparation ◽  
Monoamine Oxidase Inhibitor ◽  
Oxidase Inhibitor ◽  
Oxidative Deamination ◽  
Radioactive Precursor ◽  
Monkey Liver ◽  
Hydroxyphenylacetic Acid ◽  
Low Activity

Tyramine was conjugated with sulphate by extracts of monkey intestine and livers of monkey, rat, mouse, guinea pig and man. The activity measured in monkey intestine was almost three times that of monkey liver. Labelled tyramine sulphate synthesized from [14C] tyramine, [3H] tyramine or Na235SO4, on acid hydrolysis, released its radioactive precursor. Liver extracts of monkey, rat, mouse and guinea pig synthesized respectively 145,66,21 and 6 pmol of [14C] tyramine sulphate/min per mg of protein. Except with the monkey, intestine exhibited very low activity. trans-2-Phenylcyclopropylamine, a monoamine oxidase inhibitor, was added as a routine to the enzyme preparation, as its omission resulted in the production of p-hydroxyphenylacetic acid in appreciable amounts. This oxidative deamination of tyramine, however, did not decrease the sulpho-conjugation of tyramine. The low Km (9.1 μM) of sulphotransferase for tyramine is probably responsible.

scholarly journals The biosynthesis of tyramine glucuronide by liver microsomal fractions

1977 ◽  
Vol 164 (3) ◽  
pp. 529-531 ◽  
Author(s):  
K P Wong
Keyword(s):  
Monoamine Oxidase ◽  
Guinea Pig ◽  
Glucuronic Acid ◽  
Monoamine Oxidase Inhibitor ◽  
Oxidase Inhibitor ◽  
Freezing And Thawing ◽  
Monkey Liver ◽  
Specific Activities ◽  
Low Activity

Labelled tyramine glucuronide was synthesized in vitro from UDP-[14C]glucuronic acid, [14C]tyramine or [3H]tyramine. The glucuronidation was carried out at pH9.2 in the presence of a monoamine oxidase inhibitor, trans-2-phenylcyclopropylamine. The Km values for tyramine were 69 and 125 micrometer and those for UDP-glucuronic acid were 260 and 290 micrometer respectively for guinea-pig and rat liver microsomal preparatons. The specific activities of microsomal glucuronyltransferase measured in fresh hepatic preparations of guinea pig, mouse and rat were respectively 601, 251 and 235 pmol of [14C]tyramine glucuronide/min per mg of protein. Increase in activity ranged from 2- to 6-fold in preparations which were frozen and thawed once and 5.4- to 10-fold when the freezing and thawing was repeated. Rabbit liver has very low activity, and monkey liver and intestine were completely devoid of this conjugating capacity.

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.

scholarly journals A METHOD FOR THE FINE STRUCTURAL LOCALIZATION OF MONOAMINE OXIDASE

1969 ◽  
Vol 17 (5) ◽  
pp. 331-340 ◽  
Author(s):  
MARGARET C. BOADLE ◽  
FLOYD E. BLOOM
Keyword(s):  
Monoamine Oxidase ◽  
Monoamine Oxidase Inhibitor ◽  
Reaction Medium ◽  
Oxidase Inhibitor ◽  
Kidney Cortex ◽  
Tetrazolium Salt ◽  
Oxidative Deamination ◽  
Structural Localization ◽  
Outer Membranes ◽  
Dense Deposits

The light microscopic histochemical method for the demonstration of monoamine oxidase depends upon the reduction of a tetrazolium salt to a dark colored insoluble formazan by the aldehyde which is produced by oxidative deamination of tryptamine. This method has been adapted for electron microscopy by use of an osmiophilic ditetrazolium salt, thiocarbamyl nitroblue tetrazolium. Guinea pig kidney cortex, a rich source of monoamine oxidase, was fixed in 2% buffered paraformaldehyde, cut into 5O-8O-µ frozen sections, washed in buffered sucrose and incubated in the reaction medium at 37°. The reaction was terminated by rinsing in buffered sucrose. Tissues were exposed to 1% buffered OsO4 for 1 hr and then embedded in Araldite. Electron-dense deposits were observed between the inner and outer membranes of mitochondria in cells of the proximal tubules. These deposits were absent from controls from which substrate had been omitted and were not seen in experimental tissues treated with a monoamine oxidase inhibitor, parnate, in tissues incubated at 0° instead of 37°C or in tissues overfixed with 4% paraformaldehyde.

THE INFLUENCE OF IPRONIAZID AND PYROGALLOL ON THE THERMOGENIC EFFECTS OF NORADRENALINE

1962 ◽  
Vol 40 (1) ◽  
pp. 631-638 ◽  
Author(s):  
Gordon E. Johnson ◽  
E. A. Sellers
Keyword(s):  
Monoamine Oxidase ◽  
Wistar Rats ◽  
Monoamine Oxidase Inhibitor ◽  
Oxidase Inhibitor ◽  
Primary Reaction ◽  
Oxidative Deamination ◽  
Methyl Transferase

The effects of administering a monoamine oxidase inhibitor (iproniazid) or an inhibitor of catechol-O-methyl transferase (pyrogallol) on the calorigenic response produced by injecting noradrenaline intravenously or subcutaneously to Wistar rats are described. The influence of isoniazid on the calorigenic response to subcutaneously administered noradrenaline was also studied. The effects of syrosingopine and tetrabenazine, with and without inhibitors, and of dl-normetanephrine, were also observed. Inhibition of monoamine oxidase increased and prolonged the calorigenic response to exogenous noradrenaline or to noradrenaline released endogenously. Isoniazid, chemically related to iproniazid but not an inhibitor of monoamine oxidase, or pyrogallol, caused little change in the calorigenic response. Thus oxidative deamination appears to be the primary reaction responsible for the termination of the calorigenic response.

THE INFLUENCE OF IPRONIAZID AND PYROGALLOL ON THE THERMOGENIC EFFECTS OF NORADRENALINE

1962 ◽  
Vol 40 (5) ◽  
pp. 631-638 ◽  
Author(s):  
Gordon E. Johnson ◽  
E. A. Sellers
Keyword(s):  
Monoamine Oxidase ◽  
Wistar Rats ◽  
Monoamine Oxidase Inhibitor ◽  
Oxidase Inhibitor ◽  
Primary Reaction ◽  
Oxidative Deamination ◽  
Methyl Transferase

The effects of administering a monoamine oxidase inhibitor (iproniazid) or an inhibitor of catechol-O-methyl transferase (pyrogallol) on the calorigenic response produced by injecting noradrenaline intravenously or subcutaneously to Wistar rats are described. The influence of isoniazid on the calorigenic response to subcutaneously administered noradrenaline was also studied. The effects of syrosingopine and tetrabenazine, with and without inhibitors, and of dl-normetanephrine, were also observed. Inhibition of monoamine oxidase increased and prolonged the calorigenic response to exogenous noradrenaline or to noradrenaline released endogenously. Isoniazid, chemically related to iproniazid but not an inhibitor of monoamine oxidase, or pyrogallol, caused little change in the calorigenic response. Thus oxidative deamination appears to be the primary reaction responsible for the termination of the calorigenic response.

Distribution, Metabolism, and Disappearance of Intraventricularly Injected p-Tyramine in the Rat

1974 ◽  
Vol 52 (5) ◽  
pp. 374-381 ◽  
Author(s):  
P. H. Wu ◽  
Alan A. Boulton
Keyword(s):  
Cerebral Cortex ◽  
Monoamine Oxidase ◽  
Monoamine Oxidase Inhibitor ◽  
Brain Regions ◽  
Oxidase Inhibitor ◽  
Neutral Fraction ◽  
First Order ◽  
Metabolic Products ◽  
Hydroxyphenylacetic Acid ◽  
Presence And Absence

The major cerebral metabolic products of intraventricularly injected p-tyramine were octopamine and p-hydroxyphenylacetaldehyde. Only tiny amounts of p-hydroxyphenylacetic acid and p-hydroxyphenylethanol were found and these were located in the cerebral cortex (i.e. 'rest'). In brain regions isolated in the absence of pargyline the principal metabolite was p-hydroxyphenylacetaldehyde recovered in an acidic–neutral fraction; in the presence of pargyline, however, the majority of the label was associated with the amines tyramine and octopamine. In the caudate nucleus octopamine was essentially absent both in the presence and absence of pargyline.The loss of octopamine from all regions in the presence of pargyline was approximately exponential (i.e. first order) whereas in the absence of the monoamine oxidase inhibitor the loss was more complicated than first order. In most cases the loss of p-tyramine was greater than first order. Approximate half-lives based on these clearance values indicated a rapid turnover for p-tyramine and octopamine in all regions both in the presence and absence of pargyline.

Possible antidepressant/mania-inducing effects of methionine: a reappraisal of the effects of methionine in chronic psychosis using modern diagnostic criteria

1989 ◽  
Vol 4 (3) ◽  
pp. 175-181
Author(s):  
J.F. Lipinski ◽  
R.C. Alexander
Keyword(s):  
Monoamine Oxidase ◽  
Diagnostic Criteria ◽  
Monoamine Oxidase Inhibitor ◽  
Manic Episode ◽  
Oxidase Inhibitor ◽  
Descriptive Data ◽  
Antidepressant Effects ◽  
Chronic Psychosis

SummaryThe authors have reviewed 13 published studies on methionine administration, usually in combination with a monoamine oxidase inhibitor (MAOI), to chronically psychotic patients, using modern (DSM-III) diagnostic criteria. Four of these studies contained sufficient descriptive data to allow reappraisal of the effects. The results of the review suggest that a proportion of the patients experienced the induction of a manic episode/antidepressant effects rather than the reported worsening of schizophrenia while treated with a methionine-MAOI combination. It is suggested that these observations are consistent with recent findings that S-adenosyl-L-methionine (SAMe) has antidepressant and mania-inducing effects.

ROLE OF AN ENDOGENOUS MONOAMINE OXIDASE INHIBITOR, ISATIN, IN SHRSP BRAIN

1995 ◽  
Vol 22 (s1) ◽  
pp. S86-S87 ◽  
Author(s):  
N. Hamaue ◽  
T. Endo ◽  
M. Hirafuji ◽  
N. Yamazaki ◽  
H. Togashi ◽  
...  
Keyword(s):  
Monoamine Oxidase ◽  
Monoamine Oxidase Inhibitor ◽  
Oxidase Inhibitor

Monoamine oxidase inhibitor usage in Hawaii

2010 ◽  
Vol 3 (4) ◽  
pp. 213-215
Author(s):  
Junji Takeshita ◽  
Deborah Goebert ◽  
John Huh ◽  
Brett Lu ◽  
Diane Thompson ◽  
...  
Keyword(s):  
Monoamine Oxidase ◽  
Monoamine Oxidase Inhibitor ◽  
Oxidase Inhibitor

Identification of Kaempferol as a Monoamine Oxidase Inhibitor and Potential Neuroprotectant in Extracts ofGinkgo BilobaLeaves

2000 ◽  
Vol 52 (4) ◽  
pp. 451-459 ◽  
Author(s):  
B. D. SLOLEY ◽  
L. J. URICHUK ◽  
P. MORLEY ◽  
J. DURKIN ◽  
J. J. SHAN ◽  
...  
Keyword(s):  
Monoamine Oxidase ◽  
Monoamine Oxidase Inhibitor ◽  
Oxidase Inhibitor
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