scholarly journals Ultrastructural cytochemistry of p-N,N-dimethylamino-beta-phenethylamine (DAPA) oxidation reactions. "activation" and inhibition studies.

1976 ◽  
Vol 24 (3) ◽  
pp. 540-555 ◽  
Author(s):  
W A Shannon ◽  
H L Wasserkrug ◽  
A M Seligman
Keyword(s):  
Monoamine Oxidase ◽  
Diamine Oxidase ◽  
Amine Oxidase ◽  
The Other ◽  
Oxidation Reactions ◽  
Fixed Tissue ◽  
Tetrazolium Chloride ◽  
Ultrastructural Cytochemistry ◽  
Inhibition Studies ◽  
Reaction Media

The oxidation of p-N,N-dimethylamino-beta-phenethylamine (DAPA) by amine oxidase(s) (AO), i.e., diamine oxidase (DAO), monoamine oxidase (MAO) and/or possibly other oxidases, has been previously demonstrated. This study reports the results of variations in fixation procedures and the incorporation of a series of possible "activators" and inhibitors into the DAPA oxidase (DAPAO) and DAPAO-BSPT [2-(2'-benzothiazolyl)-5-styryl-3-(4'-phthalhydrazidyl) tetrazolium chloride] reaction media in an attempt to elucidate the oxidase(s) involved. Results of these studies are indicative of at least two different oxidases acting preferentially on one or the other of the two systems. The presence of MAO, especially in unfixed tissue, and DAO, especially in fixed tissue, is denoted and that of other oxidase(s) is connoted.

scholarly journals Site-specific expression of amine oxidases in breast cancer metastases

Tumor Biology ◽  
2018 ◽  
Vol 40 (5) ◽  
pp. 101042831877682 ◽  
Author(s):  
Yoon Jin Cha ◽  
Woo Hee Jung ◽  
Ja Seung Koo
Keyword(s):  
Breast Cancer ◽  
Metastatic Breast Cancer ◽  
Monoamine Oxidase ◽  
Diamine Oxidase ◽  
Amine Oxidase ◽  
Lung Metastases ◽  
Lysyl Oxidase ◽  
Metastatic Breast ◽  
Monoamine Oxidase B ◽  
Related Proteins

We aimed to evaluate the expression of amine oxidase-related proteins in metastatic breast cancer tissue and determine its clinical implication. A tissue microarray was constructed from a total of 126 metastatic breast tumors (31 bone metastases (24.6%), 36 brain metastases (28.6%), 11 liver metastases (8.7%), and 48 lung metastases (38.1%)). Immunohistochemical staining for amine oxidase-related proteins (lysyl oxidase, diamine oxidase, and monoamine oxidase A and B) was performed. In metastatic breast cancer tissue, lysyl oxidase ( p = 0.001), tumoral diamine oxidase ( p = 0.003), stromal diamine oxidase ( p = 0.047), and stromal monoamine oxidase B ( p = 0.002) were differentially expressed in different metastatic sites. Bone metastases showed low expression of lysyl oxidase, tumoral diamine oxidase, and stromal diamine oxidase. We observed high expression of lysyl oxidase in brain metastases, tumoral diamine oxidase in liver metastases, stromal diamine oxidase in lung metastases, and stromal monoamine oxidase B in bone metastases. Lysyl oxidase positivity was associated with progesterone receptor negativity ( p = 0.001), and monoamine oxidase A positivity was associated with human epidermal growth factor receptor-2 negativity ( p = 0.003) and the luminal A subtype ( p = 0.003). On univariate analysis shorter overall survival was associated with stromal diamine oxidase negativity ( p = 0.008), especially in lung metastases ( p = 0.025), and stromal monoamine oxidase B positivity ( p < 0.001). Stromal monoamine oxidase B positivity was an independent prognostic factor for shorter overall survival in multivariate Cox analysis (hazard ratio, 4.069; 95% confidence interval, 1.649–10.04; p = 0.002). Finally, in metastatic breast cancer, amine oxidase-related proteins were differentially expressed in a manner specific to metastatic site, and stromal monoamine oxidase B expression was correlated with prognosis.

scholarly journals Ultrastructural cytochemistry of p-N,N-dimethylamino-beta-phenethylamine (DAPA) oxidation reactions.

1976 ◽  
Vol 24 (3) ◽  
pp. 527-539 ◽  
Author(s):  
W A Shannon ◽  
H L Wasserkrug ◽  
R E Plapinger ◽  
A M Seligman
Keyword(s):  
Oxidation Reaction ◽  
Amine Oxidase ◽  
Oxidative Polymerization ◽  
Tetrazolium Salt ◽  
Oxidation Reactions ◽  
Reaction Products ◽  
Schiff’S Base ◽  
Tetrazolium Chloride ◽  
Pig Kidney ◽  
Base Formation

The ultracytochemical localization of amine oxidase (AO) activity is demonstrated with a new substrate, p-N,N-dimethylamino-beta-phenethylamine (DAPA). DAPA was designed to yield a stronger reducing agent on oxidation by monoamine oxidase (MAO) than is obtained from the MAO substrate, tryptamine, upon oxidation. Thus MAO and possibly other oxidase(s) can be demonstrated with DAPA and the tetrazolium salt, 2-(2'-benzothiazolyl)-5-styryl-3-(4'-phthalhydrazidyl) tetrazolium chloride (BSPT). The latter is a nonosmiophilic tetrazolium salt which is reduced to an osmiophilic formazan. In addition, DAPA itself demonstrates AO activity ultracytochemically with and without BSPT. We speculate that either oxidative polymerization of DAPA or Schiff's base formation with protein after aldehyde formation is responsible for the latter reaction, which is made permanent for ultracytochemical localization by osmication at a later step. DAPA oxidation reaction products are demonstrated in guinea pig kidney, specifically in the endoplasmic reticulum, nuclear envelope and mitochondrial outer compartments and cristae. Differences in reaction product characteristics and localization in relation to formaldehyde fixation and the localization of reaction product in mitochondrial cristae, as well as outer compartments, suggest that DAPA oxidation is mediated through one or more MAOs and possible other oxidases.

Differentiation of monoamine oxidase and diamine oxidase

1962 ◽  
Vol 11 (3) ◽  
pp. 177-182 ◽  
Author(s):  
W.P. Burkard ◽  
K.F. Gey ◽  
A. Pletscher
Keyword(s):  
Monoamine Oxidase ◽  
Diamine Oxidase

scholarly journals Monoamine Oxidase and Semicarbazide-Sensitive Amine Oxidase Kinetic Analysis in Mesenteric Arteries of Patients With Type 2 Diabetes

2011 ◽  
pp. 309-315 ◽  
Author(s):  
S. F. NUNES ◽  
I. V. FIGUEIREDO ◽  
J. S. PEREIRA ◽  
E. T. DE LEMOS ◽  
F. REIS ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Monoamine Oxidase ◽  
Kinetic Parameters ◽  
Amine Oxidase ◽  
Mesenteric Arteries ◽  
Patient Age ◽  
Mao B ◽  
Mao A ◽  
Type 2 Diabetic

Monoamine oxidase (MAO, type A and B) and semicarbazide-sensitive amine oxidase (SSAO) metabolize biogenic amines, however, the impact of these enzymes in arteries from patients with type 2 diabetes remains poorly understood. We investigated the kinetic parameters of the enzymes to establish putative correlations with noradrenaline (NA) content and patient age in human mesenteric arteries from type 2 diabetic patients. The kinetic parameters were evaluated by radiochemical assay and NA content by high-performance liquid chromatography (HPLC). The activity of MAO-A and SSAO in type 2 diabetic vascular tissues was significantly lower compared to the activity obtained in non-diabetic tissues. In the correlation between MAO-A (Km) and NA content, we found a positive correlation for both the diabetic and non-diabetic group, but no correlation was established for patient age. In both groups, MAO-B (Vmax) showed a negative correlation with age. The results show that MAO-A and SSAO activities and NA content of type 2 diabetic tissues are lower compared to the non-diabetic tissues, while MAO-B activity remained unchanged. These remarks suggest that MAO-A and SSAO may play an important role in vascular tissue as well as in the vascular pathophysiology of type 2 diabetes.

scholarly journals The amine oxidases of human placenta and pregnancy plasma

1974 ◽  
Vol 139 (1) ◽  
pp. 169-181 ◽  
Author(s):  
William G. Bardsley ◽  
M. James C. Crabbe ◽  
Ian V. Scott
Keyword(s):  
Diamine Oxidase ◽  
Amine Oxidase ◽  
Enzyme System ◽  
Placental Tissue ◽  
Amine Oxidases ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Ping Pong ◽  
Normal Human ◽  
Rate Limiting

1. The purification of monoamine oxidase and diamine oxidase from normal human term placental tissue is described. 2. The properties of these enzymes are reported and compared with the properties of unpurified human pregnancy plasma. 3. This comparison shows that the amine oxidase of pregnancy plasma has properties corresponding to purified placental diamine oxidase, suggesting a placental origin for the plasma enzyme system. 4. Detailed kinetic study of the purified placental diamine oxidase suggests that it has a Ping Pong sequence, a mechanism of action and rate-limiting step similar to the diamine oxidase of pig kidney. 5. It is suggested that the enzyme system is important in protecting the foeto-placental unit from excesses of biogenic amines.

scholarly journals Copper Complexes of Benzoylacetone Bis-Thiosemicarbazones: Metal and Ligand Based Redox Reactivity

2021 ◽  
Vol 74 (1) ◽  
pp. 34 ◽  
Author(s):  
Jessica K. Bilyj ◽  
Jeffrey R. Harmer ◽  
Paul V. Bernhardt
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Cyclic Voltammetry ◽  
Copper Complexes ◽  
Atmospheric Oxygen ◽  
The Other ◽  
Oxidation Reactions ◽  
Paramagnetic Resonance ◽  
Time Resolved ◽  
Vis Spectroscopy ◽  
Electron Paramagnetic

Bis-thiosemicarbazones derived from the β-diketone benzoylacetone (H3banR, R=Me, Et, Ph) are potentially tetradentate N2S2 ligands whose coordination chemistry with copper is reported. In the absence of oxygen and in the presence of base they form anionic CuII complexes of the fully deprotonated ligands [CuII(banR)]–. Upon exposure to atmospheric oxygen they undergo a complex series of reactions leading to two types of products; one a ligand oxidised ketone complex [CuII(banRO)] and the other an unprecedented dimeric di-CuIII complex [(CuIII(banR))2] depending on the R substituent. Time-resolved UV-vis spectroscopy, cyclic voltammetry, spectroelectrochemistry, and electron paramagnetic resonance (EPR) spectroscopy have been used to identify intermediates on the way to stable products formed under both anaerobic and aerobic conditions. It is found that both ligand-centred and Cu-centred oxidation reactions are occurring in parallel leading to this unusually complicated mixture of products.

scholarly journals Response of diamine oxidase and other plasma copper biomarkers to various dietary copper intakes in the rat and evaluation of copper absorption with a stable isotope

2000 ◽  
Vol 83 (5) ◽  
pp. 561-568 ◽  
Author(s):  
C. Feillet-Coudray ◽  
C. Coudray ◽  
D. Bayle ◽  
E. Rock ◽  
Y. Rayssiguier ◽  
...  
Keyword(s):  
Urinary Excretion ◽  
Intestinal Absorption ◽  
Diamine Oxidase ◽  
Control Diet ◽  
The Other ◽  
Control Group ◽  
Deficient Diet ◽  
Apparent Absorption ◽  
Cu Deficiency ◽  
Cu Isotope

There is a lack of agreement on index of Cu status and reliable and sensitive biomarkers are still required. The purpose of this present work was to assess in rats the sensitivity of diamine oxidase (DAO) activity, a recently proposed biomarker, to modifications in dietary Cu intake in comparison with other plasma biomarkers of Cu status. We also evaluated the effect of Cu dietary level on Cu and Zn intestinal absorption. Results showed that plasma Cu and plasma caeruloplasmin were significantly decreased at day 8 compared with the control group (7·4 mg Cu/kg diet) while DAO activity was significantly decreased at day 12 of the deficient diet (0·61 mg Cu/kg diet). Cu supplementation (35 mg Cu/kg diet) had no effect on any of the studied biomarkers of Cu status. In Cu-deficient rats plasma Cu and DAO activities were normalized 4 d after return to the control diet while caeruloplasmin was normalized later, at day 11. Apparent absorption values (%) of total Cu or65Cu isotope were significantly increased in the Cu-deficient rats compared with the other groups and similar in the control and the Cu-supplemented groups. The urinary excretion of total Cu or65Cu isotope were increased in the Cu-supplemented group compared with the other two groups. Both apparent absorption and urinary excretion of total Zn or67Zn isotope remained unchanged in the three experimental groups. In conclusion, DAO activity seemed to be less sensitive to Cu deficiency than plasma Cu or caeruloplasmin concentrations. The present study also showed a significant increase in Cu intestinal absorption with dietary Cu restriction but no decrease with Cu supplementation in the rat.

scholarly journals Progress, Challenge, and Perspective of Bimetallic TiO2-Based Photocatalysts

2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
Anna Zielińska-Jurek
Keyword(s):  
Photocatalytic Activity ◽  
The Other ◽  
Light Irradiation ◽  
Oxidation Reactions ◽  
Environmental Application ◽  
Metal Structures ◽  
Highly Active ◽  
Level Of Activity ◽  
Wide Wavelength Range ◽  
Hydrogenation Reactions

Bimetallic TiO2-based photocatalysts have attracted considerable attention in recent years as a class of highly active catalysts and photocatalysts under both UV and Vis light irradiation. Bimetallic noble metal structures deposited on TiO2possess the ability to absorb visible light, in a wide wavelength range (broad LSPR peak), and therefore reveal the highest level of activity as a result of utilization of a large amount of incident photons. On the other hand they can enhance the rate of trapping photoexcited electrons and inhibit the recombination process due to the capability of the storage of photoexcited electrons. Based on literature two groups of bimetallic photocatalysts were distinguished. The first group includes bimetallic TiO2photocatalysts (BMOX), highly active under UV and Vis light irradiation in a variety of oxidation reactions, and the second group presents bimetallic photocatalysts (BMRED) exceptionally active in hydrogenation reactions. This review summarizes recent advances in the preparation and environmental application of bimetallic TiO2-based photocatalysts. Moreover, the effects of various parameters such as particle shape, size, amount of metals, and calcination on the photocatalytic activity of bimetallic TiO2-based photocatalysts are also discussed.

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