Thyroid iodide transport is reduced by administration of monoamine oxidase A inhibitors to rats

1994 ◽  
Vol 143 (2) ◽  
pp. 303-308 ◽  
Author(s):  
A M Cabanillas ◽  
A M Masini-Repiso ◽  
M E Costamagna ◽  
C Pellizas ◽  
A H Coleoni

Abstract The present work was addressed to study a possible relationship between monoamine oxidase (MAO) and the thyroid iodide transport mechanism. Normal rats treated with clorgyline (a selective MAO-A inhibitor) or tranylcypromine (a non-selective MAO inhibitor) showed a significantly diminished thyroid MAO activity, while deprenyl and pargyline (MAO-B inhibitors) did not modify the thyroidal enzyme activity with respect to the control group. Under these conditions, in vivo iodide transport was reduced both by clorgyline and tranylcypromine administration whereas it remained unchanged after treatment with MAO-B inhibitors. The effect of MAO inhibitors on thyroid MAO activity and in vivo iodide transport was also evaluated in rats treated with exogenous thyrotrophin (TSH) after endogenous TSH secretion blockade produced by T4 administration. In this condition, thyroid MAO activity was significantly lowered by clorgyline and was not modified by deprenyl. In contrast to the results observed in normal rats, in vivo iodide transport in TSH-treated rats remained unaltered after treatment either with clorgyline or deprenyl. MAO activity evaluated in bovine thyroid follicles in primary culture was highly sensitive to low concentrations of clorgyline (<10 nmol/l) and relatively insensitive to deprenyl, a finding that indicates a predominance of the MAO-A isoform in the follicular cells in culture. When clorgyline (0·1 and 1 μmol/l) or deprenyl (1 μmol/l) were added to the culture medium, no modifications in the active transport of iodide were observed. These results indicate the absence of a direct linkage between thyroid MAO activity and the active iodide transport. MAO inhibitors (particularly MAO-A inhibitors) do not appear to be responsible for an in vivo diminished thyroid iodide uptake through a direct action on the iodide transport mechanism. An indirect effect of MAO-A inhibitors on thyroid iodide transport mediated by the accumulation of monoamines in neuroendocrine areas involved in TSH regulation is suggested. Journal of Endocrinology (1994) 143, 303–308

Metabolites ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 258
Author(s):  
Rajbir Singh ◽  
Sandeep Chandrashekharappa ◽  
Praveen Kumar Vemula ◽  
Bodduluri Haribabu ◽  
Venkatakrishna Rao Jala

Urolithins are gut microbial metabolites derived from ellagitannins (ET) and ellagic acid (EA), and shown to exhibit anticancer, anti-inflammatory, anti-microbial, anti-glycative and anti-oxidant activities. Similarly, the parent molecules, ET and EA are reported for their neuroprotection and antidepressant activities. Due to the poor bioavailability of ET and EA, the in vivo functional activities cannot be attributed exclusively to these compounds. Elevated monoamine oxidase (MAO) activities are responsible for the inactivation of monoamine neurotransmitters in neurological disorders, such as depression and Parkinson’s disease. In this study, we examined the inhibitory effects of urolithins (A, B and C) and EA on MAO activity using recombinant human MAO-A and MAO-B enzymes. Urolithin B was found to be a better MAO-A enzyme inhibitor among the tested urolithins and EA with an IC50 value of 0.88 µM, and displaying a mixed mode of inhibition. However, all tested compounds exhibited higher IC50 (>100 µM) for MAO-B enzyme.


2020 ◽  
Vol 20 (18) ◽  
pp. 1593-1600 ◽  
Author(s):  
Riccardo Concu ◽  
Michael González-Durruthy ◽  
Maria Natália D.S. Cordeiro

Introduction: Monoamine oxidase inhibitors (MAOIs) are compounds largely used in the treatment of Parkinson’s disease (PD), Alzheimer’s disease and other neuropsychiatric disorders since they are closely related to the MAO enzymes activity. The two isoforms of the MAO enzymes, MAO-A and MAO-B, are responsible for the degradation of monoamine neurotransmitters and due to this, relevant efforts have been devoted to finding new compounds with more selectivity and less side effects. One of the most used approaches is based on the use of computational approaches since they are time and money-saving and may allow us to find a more relevant structure-activity relationship. Objectives: In this manuscript, we will review the most relevant computational approaches aimed at the prediction and development of new MAO inhibitors. Subsequently, we will also introduce a new multitask model aimed at predicting MAO-A and MAO-B inhibitors. Methods: The QSAR multi-task model herein developed was based on the use of the linear discriminant analysis. This model was developed gathering 5,759 compounds from the public dataset Chembl. The molecular descriptors used was calculated using the Dragon software. Classical statistical tests were performed to check the validity and robustness of the model. Results: The herein proposed model is able to correctly classify all the 5,759 compounds. All the statistical performed tests indicated that this model is robust and reproducible. Conclusion: MAOIs are compounds of large interest since they are largely used in the treatment of very serious illness. These inhibitors may lose efficacy and produce severe side effects. Due to this, the development of selective MAO-A or MAO-B inhibitors is crucial for the treatment of these diseases and their effects. The herein proposed multi-target QSAR model may be a relevant tool in the development of new and more selective MAO inhibitors.


2017 ◽  
Vol 12 (4) ◽  
pp. 1934578X1701200 ◽  
Author(s):  
Maria Angélica Recalde-Gil ◽  
Luiz Carlos Klein-Júnior ◽  
Carolina dos Santos Passos ◽  
Juliana Salton ◽  
Sérgio Augusto de Loreto Bordignon ◽  
...  

Garcinia gardneriana is chemically characterized by the presence of biflavonoids. Taking into account that flavonoids are able to inhibit monoamine oxidase (MAO) activity, in the present study, the chemical composition of the branches’ extract of the plant is described for the first time and the MAO inhibitory activity of the isolated biflavonoids was evaluated. Based on spectroscopic and spectrometric data, it was possible to identify volkesiflavone, morelloflavone (1), Gb-2a (2) and Gb-2a-7- O-glucoside (3) in the ethyl acetate fraction from ethanol extract of the branches. Compounds 1-3 were evaluated in vitro and demonstrated the capacity to inhibit MAO-A activity with an IC50 ranging from 5.05 to 10.7 μM, and from 20.7 to 66.2 μM for MAO-B. These inhibitions corroborate with previous IC50 obtained for monomeric flavonoids, with a higher selectivity for MAO-A isoform. The obtained results indicate that biflavonoids might be promising structures for the identification of new MAO inhibitory compounds.


2012 ◽  
Vol 24 (6) ◽  
pp. 369-373
Author(s):  
Yuji Kitaichi ◽  
Takeshi Inoue ◽  
Shin Nakagawa ◽  
Shuken Boku ◽  
Tsukasa Koyama

Kitaichi Y, Inoue T, Nakagawa S, Boku S, Koyama T. Effects of combined treatment with clorgyline and selegiline on extracellular noradrenaline and serotonin levels.Objective Combined treatment with clorgyline, an irreversible monoamine oxidase (MAO)-A inhibitor, and selegiline, an irreversible MAO-B inhibitor, reportedly increases extracellular serotonin levels in the raphe nuclei more than clorgyline does alone. However, the effects of combination of these MAO inhibitors on extracellular noradrenaline have not been reported.Methods Using in vivo microdialysis, we measured extracellular noradrenaline and serotonin levels after administration of clorgyline and/or selegiline in the medial prefrontal cortex of rats.Results Administration of clorgyline (10 mg/kg) significantly increased both extracellular serotonin and noradrenaline levels. Combined treatment using clorgyline (10 mg/kg) and selegiline (3 mg/kg) increased extracellular serotonin and noradrenaline levels more than each drug alone did.Conclusions These findings of this study suggest the augmented antidepressant action of the combination of MAO-A inhibition and MAO-B inhibition. The addition of a MAO-A inhibitor to selegiline or increasing dose of selegiline to achieve full MAO-A inhibition might be the promising strategy for the antidepressant treatment in partial responders or non-responders to selegiline.


2020 ◽  
Vol 7 ◽  
Author(s):  
Dilara Karaman ◽  
Kemal YELEKCI ◽  
Serkan ALTUNTAS

The research of ligand-protein interactions with in silico molecular modeling studies on the atomic level gives an opportunity to be understood the pharmacokinetic metabolism of anti-depressant drug candidates. Monoamine oxidase (MAO) enzymes are important targets for the treatment of depressive disorder. MAOs have two isoforms as MAO-A and MAO-B being responsible for catalyzing of neurological amines. In this study a new series of coumarin derivatives were designed for selective and reversible inhibition of MAO-A enzyme. 3rd, 5th and 7th positions were selected to be placed of five different side groups. Docking procedures of each ligand in M series of these novel 125 compounds were executed with 10 runs by using AutoDock4.2 software. Docking results were analyzed via Discovery Studio 3.1 (Biovia Inc.). The most promising compounds were M118 and M123 according to selectivity index, SI (MAO-B/MAO-A)=180 fold and 209 fold and Ki values 7.25 nM and 12.01 nM, respectively. Overall, the current study provided significant knowledge for the development of new anti-depressant drugs.


2009 ◽  
Vol 4 (3) ◽  
pp. 321-326
Author(s):  
Elena Kosenko ◽  
Yury Kaminsky

AbstractMitochondrial enzyme monoamine oxidase A (MAO-A) generates hydrogen peroxide (H2O2) and is up-regulated by Ca2+ and presumably by ammonia. We hypothesized that MAO-A may be under the control of NMDA receptors in hyperammonemia. In this work, the in vivo effects of single dosing with ammonia and NMDA receptor antagonist MK-801 and the in vitro effect of Ca2+ on MAO-A activity in isolated rat brain mitochondria were studied employing enzymatic procedure. Intraperitoneal injection of rats with ammonia led to an increase in MAO-A activity in mitochondria indicating excessive H2O2 generation. Calcium added to isolated mitochondria stimulated MAO-A activity by as much as 84%. MK-801 prevented the in vivo effect of ammonia, implying that MAO-A activation in hyperammonemia is mediated by NMDA receptors. These data support the conclusion that brain mitochondrial MAO-A is regulated by the function of NMDA receptors. The enzyme can contribute to the oxidative stress associated with hyperammonemic conditions such as encephalopathy and Alzheimer’s disease. The attenuation of the oxidative stress highlights MAO-A inactivation and NMDA receptor antagonists as sources of novel avenues in the treatment of mental disorders.


1997 ◽  
Vol 24 (4) ◽  
pp. 287-293 ◽  
Author(s):  
Mats Bergström ◽  
Göran Westerberg ◽  
Bengt Långström

2019 ◽  
Vol 55 (17) ◽  
pp. 2477-2480 ◽  
Author(s):  
Zhengmin Yang ◽  
Wenxiu Li ◽  
Hua Chen ◽  
Qingyuan Mo ◽  
Jun Li ◽  
...  

A series of near-infrared fluorescent probes based on inhibitor (clorgyline) structure-guided design were synthesized for the specific detection of MAO-A in cells and in vivo.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Yerkebulan Orazbekov ◽  
Mohamed A. Ibrahim ◽  
Serjan Mombekov ◽  
Radhakrishnan Srivedavyasasri ◽  
Ubaidilla Datkhayev ◽  
...  

Phytochemical analysis of the ethanolic extract of Maclura pomifera fruits yielded four new compounds (I–IV) along with eleven known compounds (V–XV). The crude extract exhibited significant activity towards cannabinoid receptors (CB1: 103.4% displacement; CB2: 68.8% displacement) and possibly allosteric interaction with δ and μ opioid receptors (−49.7 and −53.8% displacement, resp.). Compound I was found to be possibly allosteric for κ and μ opioid receptors (−88.4 and −27.2% displacement, resp.) and showed moderate activity (60.5% displacement) towards CB1 receptor. Compound II exhibited moderate activity towards cannabinoid receptors CB1 and CB2 (47.9 and 42.3% displacement, resp.). The known compounds (V–VIII) exhibited prominent activity towards cannabinoid receptors: pomiferin (V) (IC50 of 2.110 and 1.318 μM for CB1 and CB2, resp.), auriculasin (VI) (IC50 of 8.923 μM for CB1), warangalone (VII) (IC50 of 1.670 and 4.438 μM for CB1 and CB2, resp.), and osajin (VIII) (IC50 of 3.859 and 7.646 μM for CB1 and CB2, resp.). The isolated compounds were also tested for inhibition of human monoamine oxidase-A and monoamine oxidase-B enzymes activities, where all the tested compounds showed fewer inhibitory effects on MAO-A compared to MAO-B activities: auriculasin (VI) (IC50 of 1.91 and 45.98 μM for MAO-B and MAO-A, resp.).


1984 ◽  
Vol 32 (6) ◽  
pp. 667-673 ◽  
Author(s):  
E Uchida ◽  
G B Koelle

The superior cervical ganglion (SCG), pineal body (PB), and liver (L) of the rat, rabbit and cat were stained for monoamine oxidase (MAO) A and B by the tetranitro blue tetrazolium (TNBT) and coupled peroxidase ( PerOx ) methods, using 5-hydroxytryptamine (5HT), tryptamine ( Tryp ), tyramine (Tyr), and benzylamine (Bz) as substrates, and clorgyline (Cl) and deprenyl (Dep), both at 10(-7) M, as selective inhibitors. The nodose ganglion (NG) and dorsal root ganglion (DRG) of the rabbit and cat were also studied. The results with rat tissues were consistent with published quantitative findings (SCG, MAO-A much greater than B; PB, MAO-A less than or equal to B; L, MAO-A = B). In the rabbit, the findings with the SCG were similar; the MAO activities of the PB were relatively resistant to both inhibitors; the MAO of the liver required 10(-4) M concentrations of both inhibitors to produce near total inhibition, suggesting that the liver contains an MAO distinct from MAO A and B. All cat tissues examined appeared to contain almost exclusively MAO-B. In this species 5HT, which is generally considered a selective substrate for MAO-A, was oxidized by MAO-B. The findings indicate that criteria for MAO-A, -B, and other subgroups must be defined for each species and tissue.


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