THE OXIDATION OF TRYPTAMINE BY RAT LIVER AND OTHER TISSUE SUSPENSIONS

1955 ◽  
Vol 33 (1) ◽  
pp. 725-734 ◽  
Author(s):  
T. L. Sourkes ◽  
Edith Townsend ◽  
Gudrun Nan Hansen
Keyword(s):  
Absorption Spectrum ◽  
Oxygen Consumption ◽  
Monoamine Oxidase ◽  
Guinea Pig ◽  
Rat Liver ◽  
Supernatant Fraction ◽  
Ultraviolet Absorption Spectrum ◽  
Monoamine Oxidase Activity ◽  
Quantitative Changes ◽  
Qualitative Changes

Tryptamine solutions were incubated with crude suspensions of rat and guinea pig tissues in the Barcroft-Warburg apparatus. Oxygen consumption was measured. Solutions incubated for various periods of time were deproteinized with perchloric acid, and the supernatant fraction was examined in the Beckman DU spectrophotometer. Consistent and marked changes were found in the ultraviolet absorption spectrum of the tryptamine solutions. The quantitative changes have been utilized for the measurement of monoamine oxidase activity by the "substrate disappearance" method. The significance of the qualitative changes in absorption spectrum is discussed. Similar experiments with 5-hydroxytryptamine are presented. This substrate is oxidized by rat liver at about the same rate as tryptamine.

THE OXIDATION OF TRYPTAMINE BY RAT LIVER AND OTHER TISSUE SUSPENSIONS

1955 ◽  
Vol 33 (5) ◽  
pp. 725-734 ◽  
Author(s):  
T. L. Sourkes ◽  
Edith Townsend ◽  
Gudrun Nan Hansen
Keyword(s):  
Absorption Spectrum ◽  
Oxygen Consumption ◽  
Monoamine Oxidase ◽  
Guinea Pig ◽  
Rat Liver ◽  
Supernatant Fraction ◽  
Ultraviolet Absorption Spectrum ◽  
Monoamine Oxidase Activity ◽  
Quantitative Changes ◽  
Qualitative Changes

Tryptamine solutions were incubated with crude suspensions of rat and guinea pig tissues in the Barcroft-Warburg apparatus. Oxygen consumption was measured. Solutions incubated for various periods of time were deproteinized with perchloric acid, and the supernatant fraction was examined in the Beckman DU spectrophotometer. Consistent and marked changes were found in the ultraviolet absorption spectrum of the tryptamine solutions. The quantitative changes have been utilized for the measurement of monoamine oxidase activity by the "substrate disappearance" method. The significance of the qualitative changes in absorption spectrum is discussed. Similar experiments with 5-hydroxytryptamine are presented. This substrate is oxidized by rat liver at about the same rate as tryptamine.

scholarly journals The interaction of triethyltin with components of animal tissues

1968 ◽  
Vol 106 (4) ◽  
pp. 821-828 ◽  
Author(s):  
M. S. Rose ◽  
W. N. Aldridge
Keyword(s):  
Guinea Pig ◽  
Rat Liver ◽  
Subcellular Fractionation ◽  
Supernatant Fraction ◽  
Animal Tissues ◽  
Rat Blood ◽  
Specific Concentration ◽  
Tin Chloride

1. The distribution of triethyl[113Sn]tin chloride in the rat, guinea pig and hamster is not uniform, the highest concentrations being in rat blood and the liver of all three species. 2. Subcellular fractionation of rat liver, brain and kidney shows that triethyltin binds to all fractions to different extents. In the liver of the rat and guinea pig the supernatant fraction contains the largest amount and the highest specific concentration; this triethyltin is bound to a non-diffusible component. 3. Rat haemoglobin is responsible for the binding of triethyltin in rat blood (2 moles of triethyltin/mole of haemoglobin). Haemoglobins from other species have much less affinity for triethyltin. 4. A variety of other proteins do not bind triethyltin.

scholarly journals A kinetic evaluation of monoamine oxidase activity in rat liver mitochondrial outer membranes

1974 ◽  
Vol 139 (3) ◽  
pp. 645-652 ◽  
Author(s):  
Miles D. Houslay ◽  
Keith F. Tipton
Keyword(s):  
Monoamine Oxidase ◽  
Rat Liver ◽  
Oxidase Activity ◽  
Monoamine Oxidase Activity ◽  
Irreversible Inhibitor ◽  
Kinetic Evaluation ◽  
Reversible Inhibitors ◽  
Substrate Specificities ◽  
Outer Membranes ◽  
Enzyme Species

1. A preparation of mitochondrial outer membranes from rat liver can be shown to contain two kinetically distinct monoamine oxidase activities. These activities are distinguishable by their different sensitivities to the irreversible inhibitor clorgyline, and by the effect of the reversible inhibitors benzyl cyanide and 4-cyanophenol. 2. The substrate specificities of the preparation and the two enzyme species have been elucidated.

Possible isoenzymes of monoamine oxidase in rat tissues

1968 ◽  
Vol 46 (4) ◽  
pp. 295-297 ◽  
Author(s):  
H. C. Kim ◽  
A. D'Iorio
Keyword(s):  
Monoamine Oxidase ◽  
Rat Liver ◽  
Oxidase Activity ◽  
Liver Homogenate ◽  
Rat Tissues ◽  
Consistent Difference ◽  
Monoamine Oxidase Activity ◽  
Mitochondrial Monoamine Oxidase

The solubilized monoamine oxidase activity of rat liver, kidney, and brain can be separated into several bands by cellulose polyacetate membrane electrophoresis. Four such bands of activity are found in the whole liver homogenate while mitochondrial and microsomal fractions appear to have two. The activity of these bands has been assayed using three different substrates, isoamylamine, tyramine, and benzylamine. The solubilized mitochondrial monoamine oxidase activity of kidney and brain when submitted to electrophoresis is found to separate in two fractions. There is some small but consistent difference of distribution of activity when using different substrates.

Polyacrylaniide Gel Electrophoresis of Rat Liver Mitochondrial Monoamine Oxidases

1973 ◽  
Vol 51 (7) ◽  
pp. 1089-1095 ◽  
Author(s):  
J. M. Diaz Borges ◽  
A. D'Iorio
Keyword(s):  
Monoamine Oxidase ◽  
Rat Liver ◽  
Gel Electrophoresis ◽  
Oxidase Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Liver Mitochondria ◽  
The Other ◽  
Rat Liver Mitochondria ◽  
Monoamine Oxidase Activity ◽  
Tetrazolium Staining

Solubilized rat liver mitochondria were subjected to polyacrylamide gel electrophoresis. The monoamine oxidase activity was localized directly on the gel with radioactive substrates (serotonin, benzylamine, and tyramine). Serotonin and tyramine monoamine oxidase activity separated in several bands which migrated to the anode and cathode whereas benzylamine activity was localized in one band. This band was demonstrated only when the electrophoresis was run from cathode to anode. Each one of tyramine and serotonin activities could be found devoid of the other two activities. Benzylamine activity could be separated from the serotonin activity though not from the tyramine activity. The detection of monoamine oxidase with the tetrazolium staining provided a localization of the enzyme activity which was different from that observed using radioactive substrates. These results, in accordance with those previously obtained by us with sucrose gradient electrophoresis of the same preparation, support the existence of different enzymes for the oxidative deamination of benzylamine and serotonin. On the other hand our results did not eliminate the possibility of overlapping substrate specificity of tyramine activity with those of serotonin and benzylamine activities.

scholarly journals The influence of respiratory state on monoamine oxidase activity in rat liver mitochondria

1978 ◽  
Vol 176 (3) ◽  
pp. 1011-1014 ◽  
Author(s):  
G S Smith ◽  
R A Reid
Keyword(s):  
Monoamine Oxidase ◽  
Outer Membrane ◽  
Rat Liver ◽  
Oxidase Activity ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Monoamine Oxidase Activity ◽  
Oxidative Deamination ◽  
Thermodynamic State ◽  
Respiratory State

Changes in the respiratory state of rat liver mitochondria caused significant changes (up to 10-fold) in the rates of oxidative deamination of tyramine, indicating interactions between the inner coupling membrane and the monoamine oxidase sites in the outer membrane, and suggesting the possibility that monoamine oxidase is regulated by the thermodynamic state of the mitochondria.

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