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Alcolea Palafox M, Franklin Benial AM, K Rastogi V. Biomolecules of 2-Thiouracil, 4-Thiouracil and 2,4-Dithiouracil: A DFT Study of the Hydration, Molecular Docking and Effect in DNA:RNAMicrohelixes. Int J Mol Sci 2019; 20:E3477. [PMID: 31311161 PMCID: PMC6678171 DOI: 10.3390/ijms20143477] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/10/2019] [Accepted: 07/11/2019] [Indexed: 12/17/2022] Open
Abstract
The molecular structure of 2-thiouracil, 4-thiouracil and 2,4-dithiouracil was analyzed under the effect of the first and second hydration shell by using the B3LYP density functional (DFT) method, and the results were compared to those obtained for the uracil molecule. A slight difference in the water distribution appears in these molecules. On the hydration of these molecules several trends in bond lengths and atomic charges were established. The ring in uracil molecule appears easier to be deformed and adapted to different environments as compared to that when it is thio-substituted. Molecular docking calculations of 2-thiouracil against three different pathogens: Bacillus subtilis, Escherichia coli and Candida albicans were carried out. Docking calculations of 2,4-dithiouracil ligand with various targeted proteins were also performed. Different DNA: RNA hybrid microhelixes with uridine, 2-thiouridine, 4-thiouridine and 2,4-dithiouridine nucleosides were optimized in a simple model with three nucleotide base pairs. Two main types of microhelixes were analyzed in detail depending on the intramolecular H-bond of the 2'-OH group. The weaker Watson-Crick (WC) base pair formed with thio-substituted uracil than with unsubstituted ones slightly deforms the helical and backbone parameters, especially with 2,4-dithiouridine. However, the thio-substitution significantly increases the dipole moment of the A-type microhelixes, as well as the rise and propeller twist parameters.
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Affiliation(s)
- M Alcolea Palafox
- Departamento de Química-Física, Facultad de CienciasQuímicas, Universidad Complutense de Madrid, 28040 Madrid, Spain.
| | | | - V K Rastogi
- Indian Spectroscopy Society, KC 68/1, Old Kavinagar, Ghaziabad 201002, India
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Matsushima W, Herzog VA, Neumann T, Gapp K, Zuber J, Ameres SL, Miska EA. SLAM-ITseq: sequencing cell type-specific transcriptomes without cell sorting. Development 2018; 145:dev164640. [PMID: 29945865 PMCID: PMC6053661 DOI: 10.1242/dev.164640] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 06/01/2018] [Indexed: 12/13/2022]
Abstract
Cell type-specific transcriptome analysis is an essential tool for understanding biological processes in which diverse types of cells are involved. Although cell isolation methods such as fluorescence-activated cell sorting (FACS) in combination with transcriptome analysis have widely been used so far, their time-consuming and harsh procedures limit their applications. Here, we report a novel in vivo metabolic RNA sequencing method, SLAM-ITseq, which metabolically labels RNA with 4-thiouracil in a specific cell type in vivo followed by detection through an RNA-seq-based method that specifically distinguishes the thiolated uridine by base conversion. This method has successfully identified the cell type-specific transcriptome in three different tissues: endothelial cells in brain, epithelial cells in intestine and adipocytes in white adipose tissue. As this method does not require isolation of cells or RNA prior to the transcriptomic analysis, SLAM-ITseq provides an easy yet accurate snapshot of the transcriptional state in vivo.
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Affiliation(s)
- Wayo Matsushima
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
- Wellcome Trust Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Cambridge CB10 1SA, UK
| | - Veronika A Herzog
- Institute of Molecular Biotechnology, Vienna Biocenter Campus, Vienna 1030, Austria
| | - Tobias Neumann
- Research Institute of Molecular Pathology, Vienna Biocenter Campus, Vienna 1030, Austria
| | - Katharina Gapp
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
- Wellcome Trust Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Cambridge CB10 1SA, UK
| | - Johannes Zuber
- Research Institute of Molecular Pathology, Vienna Biocenter Campus, Vienna 1030, Austria
| | - Stefan L Ameres
- Institute of Molecular Biotechnology, Vienna Biocenter Campus, Vienna 1030, Austria
| | - Eric A Miska
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
- Wellcome Trust Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Cambridge CB10 1SA, UK
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Van Meulebroek L, Wauters J, Pomian B, Vanden Bussche J, Delahaut P, Fichant E, Vanhaecke L. Discovery of urinary biomarkers to discriminate between exogenous and semi-endogenous thiouracil in cattle: A parallel-like randomized design. PLoS One 2018; 13:e0195351. [PMID: 29649241 PMCID: PMC5896977 DOI: 10.1371/journal.pone.0195351] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 03/20/2018] [Indexed: 12/22/2022] Open
Abstract
In the European Union, the use of thyreostats for animal fattening purposes has been banned and monitoring plans have been established to detect potential abuse. However, this is not always straightforward as thyreostats such as thiouracil may also have a semi-endogenous origin. Therefore, this study aimed at defining urinary metabolites, which may aid in defining the origin of detected thiouracil. Hereto, a parallel-like randomized in vivo study was conducted in which calves (n = 8) and cows (n = 8) were subjected to either a control treatment, rapeseed-enriched diet to induce semi-endogenous formation, or thiouracil treatment. Urine samples (n = 330) were assessed through metabolic fingerprinting, employing liquid-chromatography and Q-ExactiveTM Orbitrap mass spectrometry. Urinary fingerprints comprised up to 40,000 features whereby multivariate discriminant analysis was able to point out significant metabolome differences between treatments (Q2(Y) ≥ 0.873). Using the validated models, a total of twelve metabolites (including thiouracil) were assigned marker potential. Combining these markers into age-dependent biomarker panels rendered a tool by which sample classification could be improved in comparison with thiouracil-based thresholds, and this during on-going thiouracil treatment (specificities ≥ 95.2% and sensitivities ≥ 85.7%), post-treatment (sensitivities ≥ 80% for ≥ 24 h after last administration), and simulated low-dose thiouracil treatment (exogenous thiouracil below 30 ng μL-1). Moreover, the metabolic relevance of revealed markers was supported by the suggested identities, for which a structural link with thiouracil could be determined in most cases. The proposed biomarker panels may contribute to a more justified decision-making in monitoring thiouracil abuse.
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Affiliation(s)
- Lieven Van Meulebroek
- Laboratory of Chemical Analysis, Department of Veterinary Public Health and Food Safety, Faculty of Veterinary Medicine, Ghent University, Salisburylaan, Merelbeke, Belgium
- * E-mail:
| | - Jella Wauters
- Laboratory of Chemical Analysis, Department of Veterinary Public Health and Food Safety, Faculty of Veterinary Medicine, Ghent University, Salisburylaan, Merelbeke, Belgium
| | - Beata Pomian
- Laboratory of Chemical Analysis, Department of Veterinary Public Health and Food Safety, Faculty of Veterinary Medicine, Ghent University, Salisburylaan, Merelbeke, Belgium
| | - Julie Vanden Bussche
- Laboratory of Chemical Analysis, Department of Veterinary Public Health and Food Safety, Faculty of Veterinary Medicine, Ghent University, Salisburylaan, Merelbeke, Belgium
| | | | - Eric Fichant
- Health Department, CER Groupe, Rue Point du Jour, Marloie, Belgium
| | - Lynn Vanhaecke
- Laboratory of Chemical Analysis, Department of Veterinary Public Health and Food Safety, Faculty of Veterinary Medicine, Ghent University, Salisburylaan, Merelbeke, Belgium
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Abou-Melha KS. Spectral and Eukaryotic DNA degradation studies for Ni(II), Pd(II), Pt(IV), Cu(II) and UO2(2+) complexes derived from thiouracil derivative. Spectrochim Acta A Mol Biomol Spectrosc 2013; 109:146-154. [PMID: 23518511 DOI: 10.1016/j.saa.2013.01.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 01/08/2013] [Accepted: 01/10/2013] [Indexed: 06/01/2023]
Abstract
A derivative of thiouracil ligand was prepared. Ni(II), Pd(II), Pt(IV), Cu(II) and UO2(2+) complexes were prepared. The elemental and different spectral tools were used for their characterization. A binegative tetradentate mode is the general coordination behavior of the ligand towards all metal ions used. The structural geometries were varied from square-planer (Pt, Pd(II)), square-pyramidal (Cu(II)) and octahedral (UO2(2+)). The geometry optimization implementing the hyperChem reveals that the Cu(II) complex is the most stable one. The thermogravimetric analysis supports the presence of solvent molecules attached with most complexes. The biological investigation was studied on different microorganisms as gram-positive, gram-negative and fungia. The Ni(II) complex shows the most toxic activity towards most organisms used. The degradation effect of DNA was studied by the use of investigated compounds and reveal that the Ni(II) and Pd(II) complexes are the most effective on the DNA degradation.
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Affiliation(s)
- Khlood S Abou-Melha
- Chemistry Department, Faculty of Science, King Khalid University, Abha, Saudi Arabia.
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Masoud MS, Soayed AA, El-Husseiny AF. Coordination modes, spectral, thermal and biological evaluation of hetero-metal copper containing 2-thiouracil complexes. Spectrochim Acta A Mol Biomol Spectrosc 2012; 99:365-372. [PMID: 23026345 DOI: 10.1016/j.saa.2012.08.084] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 08/15/2012] [Accepted: 08/31/2012] [Indexed: 06/01/2023]
Abstract
Mononuclear copper complex [CuL(NH(3))(4)]Cl(2)·0.5H(2)O and three new hetero-metallic complexes: [Cu(2)Ni(L)(2)(NH(3))(2)Cl(2)·6H(2)O] 2H(2)O(,) [Cu(3)Co(L)(4)·8H2O]Cl·4(·)5H(2)O, and [Cu(4)Co(2)Ni(L)(3)(OH)(4)(NH(3))Cl(4)·3H(2)O]4H(2)O where L is 2-thiouracil, were prepared and characterized by elemental analyses, molar conductance, room-temperature magnetic susceptibility, spectral (IR, UV-Vis and ESR) studies and thermal analyses techniques (TG, DTG and DTA). The molar conductance data revealed that [CuL(NH(3))(4)]Cl(2)·0.5H(2)O and [Cu(3)Co(L)(4)·8H2O]Cl·4.5H(2)O are electrolytes, while, [Cu(2)Ni(L)(2)(NH(3))(2)Cl(2·)6H(2)O]·2H(2)O and [Cu(4)Co(2)Ni(L)(3)(OH)(4)(NH(3))Cl(4)·3H(2)O]4H(2)O are non-electrolytes. IR spectra showed, that 2-thiouracil ligand behaves as a bidentate or tetradentate ligand. The geometry around the metal atoms is octahedral in all the prepared complexes except in [Cu(4)Co(2)Ni(L)(3)(OH)(4)(NH(3))Cl(4)·3H(2)O]4H(2)O complex where square planar environment around Co(II), Ni(II) and Cu(II) were suggested. Thermal decomposition study of the prepared complexes was monitored by TG, DTG and DTA analyses under N(2) atmosphere. The decomposition course and steps were analyzed. The order of chemical reactions (n) was calculated via the peak symmetry method and the activation parameters of the non- isothermal decomposition were computed from the thermal decomposition data. The negative values of ΔS(∗) deduced the ordered structures of the prepared complexes compared to their starting reactants. The antimicrobial activity of the prepared complexes were screened in vitro against a Gram positive, a Gram negative bacteria, a filamentous fungi and a yeast. The antimicrobial screening data showed that the studied compounds exhibited a good level of activity against Escherichia coli, Staphylococcus aureus and Candida albicans but have no efficacy against Aspergillus flavus. It was observed that [Cu(4)Co(2)Ni(L)(3)(OH)(4)(NH(3))Cl(4)·3H(2)O]4H(2)O complex showed the most intensive activity against the tested microorganisms. Trials to prepare single crystals from complexes were failed.
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Affiliation(s)
- Mamdouh S Masoud
- Department of Chemistry, Faculty of Science, Alexandria University, PO Box 426-Ibrahimia, Alexandria 21321, Egypt
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Abou-Melha KS. Elaborated studies for the ligitional behavior of thiouracil derivative towards Ni(II), Pd(II), Pt(IV), Cu(II) and UO2 ² ions. Spectrochim Acta A Mol Biomol Spectrosc 2012; 97:6-16. [PMID: 22743608 DOI: 10.1016/j.saa.2012.05.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 04/24/2012] [Accepted: 05/03/2012] [Indexed: 06/01/2023]
Abstract
A synthesis of new thiouracil derivative was carried out and deliberately investigated. A new series of complexes was prepared using Ni(II), Pd(II), Pt(IV), Cu(II) and UO(2)(+2) ions. IR spectral data proposed the coordination mod of the ligand towards each metal ion and displays the binegative pentadentate mod as the maximum mod of coordination obtained with Ni(II) and Cu(II) complexes. (1)HNMR spectrum of UO(2)(+2) complex in comparing with the free ligand spectrum supports the binegative appearance of the coordinated ligand through the ionization of CO and CS groups. The electronic spectral data as well as the magnetic moment measurements are coincide with each others to propose the square-planar geometry with Ni(II), Pd(II) and Cu(II) complexes and octahedral geometry with the others. ESR spectrum of Cu(II) complex displays axially symmetric g tensor parameters with g(11)>g(⊥)>2.0023 indicating that the [Formula: see text] orbital as a ground state with the square-planar geometry. The TG analysis for all isolated complexes were carried out to assert about the presence of water molecules physically or chemically attached with the central atom. The biological study was carried out against different microorganisms as gram negative, gram positive and fungi. The comparable data display the relative priority of Ni(II) complex in comparing with others against all organisms but, the other complexes display activity by the same with the free ligand.
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SPENCER PS, WEST GB. Further Observations on the Relationship between the Thyroid Gland and the Anaphylactoid Reaction in Rats. Int Arch Allergy Immunol 2009; 20:321-43. [PMID: 13915697 DOI: 10.1159/000229275] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Effects of Thiouracil and Sitosterol on Diet-Induced Hypercholesterolemia and Lipomatous Arterial Lesions in the Rat. Nutr Rev 2009; 18:26-27. [PMID: 13857962 DOI: 10.1111/j.1753-4887.1960.tb01635.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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FORD DH. THE EFFECT OF THYROIDECTOMY AND PROPYLTHIOURACIL TREATMENT ON THE MORPHOLOGICAL APPEARANCE OF THE NEUROSECRETORY SYSTEM OF THE RAT. Cells Tissues Organs 2008; 40:13-26. [PMID: 13823897 DOI: 10.1159/000141569] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Al Safarjalani ON, Rais R, Shi J, Schinazi RF, Naguib FNM, el Kouni MH. Modulation of 5-fluorouracil host-toxicity and chemotherapeutic efficacy against human colon tumors by 5-(Phenylthio)acyclouridine, a uridine phosphorylase inhibitor. Cancer Chemother Pharmacol 2006; 58:692-8. [PMID: 16528530 DOI: 10.1007/s00280-006-0213-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Accepted: 02/08/2006] [Indexed: 10/24/2022]
Abstract
PURPOSE The purpose of this investigation was to evaluate the effectiveness of oral 5-(phenylthio)acyclouridine (PTAU) in reducing 5-fluorouracil (FUra) host-toxicity and enhancing its chemotherapeutic efficacy against human colon tumors. PTAU is a potent and specific inhibitor of uridine phosphorylase (UrdPase, EC 2.4.2.3), the enzyme responsible for uridine catabolism. METHODS SCID mice bearing human colon DLD-1 or HCT-15 tumors were injected intraperitoneally with FUra (50, 200 or 300 mg/kg) on days 17, 24 and 31 after tumor cell inoculation. PTAU (120 mg/kg), uridine (1,320 mg/kg) or their combination was administered orally 2 or 4 h after FUra injection. Another four administrations of PTAU+uridine were given every 8 h after the first treatment with PTAU plus uridine. Survival and body weight were used to evaluate host toxicity. Tumor weight was used to evaluate the efficacy of the drugs on tumor growth. The mice were monitored for 38 days. RESULTS Administration of the maximum tolerated dose (50 mg/kg) of FUra reduced DLD-1 and HCT-15 tumor weights by 48 and 59%, respectively, at day 38 post implantation. Administration of 200 mg/kg FUra resulted in 100% mortality. Oral administration of uridine (1,320 mg/kg) alone, 2 h following the administration of 200 mg/kg FUra, did not alleviate FUra host-toxicity as all the mice died. Administration of 120 mg/kg PTAUresulted in partial rescue from this lethal dose of FUra as 63% of mice survived and tumor weights were reduced by approximately 60%. Coadministration of PTAU plus uridine resulted in complete rescue from the toxicity of FUra as 100% of the mice survived and tumor weights were reduced by 81-82%. Delaying the administration of the combination of PTAU plus uridine to 4 h post FUra treatment was less effective in rescuing from FUra toxicity as only 88% of the mice survived and tumor weights were reduced by only 62%. Administration of PTAU alone, under the same conditions, resulted in a 38% survival rate while the tumor weights were reduced by 47%. Treatment with uridine alone did not protect from FUra toxicity at the dose of 200 mg/kg as all mice died. At the higher dose of 300 mg/kg FUra, neither uridine nor PTAU alone, administered 2 h following the treatment with FUra, had any rescuing effect. On the other hand, the use of the PTAU plus uridine combination reduced the tumor weight by 79%, although this reduction in the tumor weight was accompanied by 37% mortality. There was no significant difference between DLD-1 and HCT-15 in their response to the different regimens employed in this study despite the fact that the tumors have different levels of UrdPase. CONCLUSIONS The present results demonstrate that the combination of PTAU plus uridine represents an exceptionally efficient method in increasing FUra chemotherapeutic efficacy while minimizing its host-toxicity. The efficiency of the PTAU plus uridine combination can be attributed to the extraordinary effectiveness of this combinationin raising and maintaining higher levels of uridine in vivo (Al Safarjalani et al., Cancer Chemo Pharmacol 55:541-551, 2005). Therefore, the combination of PTAU plus uridine can provide a better substitute for the large doses of uridine necessary to rescue or protect from FUra host-toxicities, without the toxic side-effects associated with such doses of uridine. This combination may also allow for the escalation of FUra doses for better chemotherapeutic efficacy against human colon carcinoma while avoiding FUra host-toxicities. Alternatively, the combination of PTAU and uridine may be useful as an antidote in the few cases when cancer patients receive a lethal overdose of FUra.
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Affiliation(s)
- Omar N Al Safarjalani
- Department of Pharmacology and Toxicology, Comprehensive Cancer Center, Center for Aids Research, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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Dasgupta A, Das S, Sarkar PK. Thyroid hormone stimulates γ-glutamyl transpeptidase in the developing rat cerebra and in astroglial cultures. J Neurosci Res 2005; 82:851-7. [PMID: 16302185 DOI: 10.1002/jnr.20657] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Hypothyroidism in the developing rat brain is associated with enhanced oxidative stress, one of the earliest manifestations of which is a decline in the level of glutathione (GSH). To investigate the role of thyroid hormone (TH) on GSH homeostasis, the effect of TH on gamma-glutamyl transpeptidase (gammaGT), the key enzyme involved in the catalysis of GSH, was studied. Hypothyroidism declined the specific activity of cerebral gammaGT at all postnatal ages examined (postnatal day 1-20) with a maximum inhibition of 42% at postnatal day 10. Intraperitoneal injection of TH to 15-day-old rat pups increased the specific activity of gammaGT by 25-30% within 4-6 hr. Treatment of primary cultures of astrocytes by TH also enhanced the specific activity of gammaGT by 30-40% within 4-6 hr. The induction of gammaGT by TH was blocked by actinomycin D or cycloheximide. gammaGT is an ectoenzyme that is normally involved in the catabolism of GSH released by astrocytes. In the presence of the gammaGT-inhibitor, acivicin, GSH released in the culture medium of astrocytes increased linearly for at least 6 hr and TH had no effect on this accumulation pattern. In the absence of acivicin, GSH content of the medium from TH-treated cells was significantly lower than that of untreated controls due to activation of gammaGT by TH and a faster processing of GSH. Because the products of gammaGT reaction are putative precursors for neuronal GSH, the activation of gammaGT by TH may be conducive to GSH synthesis in neurons and their protection from oxidative stress.
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Affiliation(s)
- Asmita Dasgupta
- Division of Neurobiology, Indian Institute of Chemical Biology, Jadavpur, Kolkata, India
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Abstract
2-Thiouracil-5-sulphonic acid N-(4-acetylphenyl) Amide (1) was reacted with a series of aromatic aldehydes giving chalcones 2 (Claisen-Schemidt reaction), some of these chalcones were reacted with urea and thiourea giving pyrimidine-2-one and pyrimidine-2 thione derivatives respectively of the type 3a,b and 4a,b. In addition many chalcones were reacted with hydroxylamine hydrochloride giving isoxazoline derivatives 5a,b. They could also reacted with phenylhydrazine to give pyrazoline derivatives 6a,b, chalcones also were reacted withethylcyano acetate and/or malononitryl in pyridine giving pyran derivatives 7a,c and 8a,c. In another pathway chalcones were epoxidised by H2O2 giving epoxides 9a,c which in turn were reacted with phenylhydrazine giving 4-hydroxypyrazoline derivatives 10a,c. In another reaction chalcones were reacted with ethylcyanoacetate in presence of amm.acetate giving pyridone derivatives 11a,d which could be prepared also in exellent yield from compound 1 by its reaction with certain aromatic aldehydes and ethylcyanoacetate in presence of ammonium acetate. Finally, compound 1 was reacted with semicarbazide giving semicarbazone intermediate 12 which in turn was reacted with thionyl chloride giving thiadiazole derivative 13. The biological effects of some of the new synthesized compounds were also investigated.
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Affiliation(s)
- O A Fathalla
- Department of Medicinal Chemistry, National Research Centre, Dokki, Cairo, Egypt.
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Al Safarjalani ON, Zhou XJ, Rais RH, Shi J, Schinazi RF, Naguib FNM, El Kouni MH. 5-(Phenylthio)acyclouridine: a powerful enhancer of oral uridine bioavailability: relevance to chemotherapy with 5-fluorouracil and other uridine rescue regimens. Cancer Chemother Pharmacol 2005; 55:541-51. [PMID: 15729584 DOI: 10.1007/s00280-004-0967-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2004] [Accepted: 08/29/2004] [Indexed: 11/30/2022]
Abstract
PURPOSE The purpose of this investigation was to evaluate the effectiveness of oral 5-(phenylthio)acyclouridine (PTAU) in improving the pharmacokinetics and bioavailability of oral uridine. PTAU is a potent and specific inhibitor of uridine phosphorylase (UrdPase, EC 2.4.2.3), the enzyme responsible for uridine catabolism. This compound was designed as a lipophilic inhibitor in order to facilitate its access to the liver and intestine, the main organs involved in uridine catabolism. PTAU is fully absorbed after oral administration with 100% oral bioavailability. METHODS Uridine (330, 660 or 1320 mg/kg) and/or PTAU (30, 45, 60, 120, 240 or 480 mg/kg) were orally administered to mice. The plasma levels of uridine, its catabolite uracil, and PTAU were measured using HPLC, and pharmacokinetic analysis was performed. RESULTS Oral PTAU up to 480 mg/kg per day is not toxic to mice. Oral PTAU at 30, 45, 60, 120 and 240 mg/kg has a prolonged plasma half-life of 2-3 h, and peak plasma PTAU concentrations (C(max)) of 41, 51, 74, 126 and 161 microM with AUCs of 70, 99, 122, 173 and 225 micromol h/l, respectively. Coadministration of uridine with PTAU did not have a significant effect on the pharmacokinetic parameters of plasma PTAU at any of the doses tested. Coadministration of PTAU (30, 45, 60 and 120 or 240 mg/kg) with uridine (330, 660 or 1320 mg/kg) elevated the concentration of plasma uridine over that following the same dose of uridine alone, a result of reduced metabolic clearance of uridine as evidenced by decreased plasma exposure (C(max) and AUC) to uracil. Plasma uridine was elevated with the increase of uridine dose at each PTAU dose tested and no plateau was reached. Coadministration of PTAU at 30, 45, 60, 120 and 240 mg/kg improved the low oral bioavailability (7.7%) of uridine administered at 1320 mg/kg by 4.3-, 5.9-, 9.9-, 11.7- and 12.5-fold, respectively, and reduced the AUC of plasma uracil (1227.8 micromol h/l) by 5.7-, 6.8-, 8.2-, 6.3-, and 6.9-fold, respectively. Similar results were observed when PTAU was coadministered with lower doses of uridine. Oral PTAU at 30, 45, 60, 120 and 240 mg/kg improved the oral bioavailability of 330 mg/kg uridine by 1.7-, 2.4-, 2.6-, 5.2- and 4.3- fold, and that of 660 mg/kg uridine by 2.3-, 2.7-, 3.3-, 4.6- and 6.7-fold, respectively. CONCLUSION The excellent pharmacokinetic properties of PTAU, and its extraordinary effectiveness in improving the oral bioavailability of uridine, could be useful to rescue or protect from host toxicities of 5-fluorouracil and various chemotherapeutic pyrimidine analogues used in the treatment of cancer and AIDS, as well as in the management of medical disorders that are remedied by the administration of uridine including CNS disorders (e.g. Huntington's disease, bipolar disorder), liver diseases, diabetic neuropathy, cardiac damage, various autoimmune diseases, and transplant rejection.
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Affiliation(s)
- Omar N Al Safarjalani
- Department of Pharmacology and Toxicology, Comprehensive Cancer Center, Center for AIDS Research, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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CHANDA R, CLAPHAM HM, McNAUGHT ML, OWEN EC. The digestibility of carotene by the cow and the goat as affected by thyroxine and thiouracil. Biochem J 2004; 50:95-9. [PMID: 14904377 PMCID: PMC1197611 DOI: 10.1042/bj0500095] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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18
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CHANDA R, OWEN EC. The effect of thyroxine and thiouracil on the composition of milk. I. The partition of phosphorus in cow milk in relation to phosphatase and other constituents. Biochem J 2004; 50:100-9. [PMID: 14904378 PMCID: PMC1197612 DOI: 10.1042/bj0500100] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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19
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Abstract
The deficit of thyroid hormone leads to several structural and physiological modifications in the auditory receptor: the outer hair cells present an immature morphology, abnormal persistence of the afferent dendrites and incomplete development of the efferent terminals. The aim of this work was to perform a quantitative and morphometric study of the spiral ganglion neurons in control and hypothyroid animals. The cochleae from both experimental groups were processed in order to obtain plastic sections. In control animals the size of the neurons increased throughout development and was larger in the basal than in the apical portion of the cochlea. In hypothyroid animals, the cell death that takes place normally during development did not occur, and there was no differentiation into types I and II neurons. The size of the neurons also increased with development in treated animals, but they were smaller than in control animals, and in this case the neurons in the apex were larger than in the base. This study shows that hypothyroidism alters the normal development of the spiral ganglion neurons.
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Affiliation(s)
- Joaquin Rueda
- Departamento de Histología y Anatomía, Facultad de Medicina, Universidad Miguel Hernández, Apdo. Correos 374, 03550 San Juan de Alicante, Spain.
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20
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Abstract
6-n-Propyl-2-thiouracil (6-PTU), the antithyroid agent, produces a time-, concentration-, and turnover-dependent inactivation of the NO synthetic capability of the neuronal nitric oxide synthase isoform irreversible by either arginine or (6R)-5,6,7,8-tetrahydro-L-biopterin. By contrast 6-PTU produces an inhibition of the cytokine-inducible and endothelial nitric oxide synthases fully reversible by arginine. The inactivation of neuronal nitric oxide synthase by 6-PTU follows first order kinetics, and is inhibited competitively by both arginine and (6R)-5,6,7,8-tetrahydro-L-biopterin, but is not accompanied by either a loss of heme-CO binding, heme fluorescence, or disassembly of dimeric structure. 2-Thiouracil behaves qualitatively identically to 6-PTU. Turnover-dependent inactivation of neuronal nitric oxide synthase by [2-14C]-2-thiouracil is accompanied by incorporation of radioactivity into the polypeptide chain. Ca2+-dependent NO formation by GH3 pituitary cells is inhibited by 6-PTU in a manner enhanced by depletion of either extracellular arginine or intracellular (6R)-5,6,7,8-tetrahydro-L-biopterin. These observations establish that 6-PTU is an alternate substrate, mechanism-based inactivator of the neuronal nitric oxide synthase isoform with the ability to suppress cellular NO formation.
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Affiliation(s)
- Donald J Wolff
- Department of Pharmacology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, NJ 08854, USA.
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21
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Abstract
2-Thiouracil-5-sulfonylchloride 1 reacted with a series of aromatic and heterocyclic amines to give 2a-j. The same compound 1 was reacted with a series of sulphonamides giving different sulphonamides of type 3a-e. On the other hand compound 1 was allowed to react with p-aminoacetophenone givining compound 4 which in turn was allowed to react with derivatives of alkyl thiosemicarbazides to give thiosemicarbazones of type 5a-e, also compound 4 was monobrominated to give compound 6 which in turn was reacted thiosemicarbazones of some aldehydes to give the corresponding thiazole derivatives 7a-f. In the same time compound 4 was reacted with a series of aromatic and heterocyclic aldehydes givining chalcones 8a-g (Claisen-Schemidt reaction). Also compound 4 was allowed to react with a series of aromatic and heterocyclic aldehydes, ethyl cyano acetate and/or malononitrile, and ammonium acetate giving pyridine derivatives 9a-d and 10a-e respectively. The biological effects of some of the new synthesized compounds was also investigated.
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Affiliation(s)
- A Fathalla
- Department of Medicinal Chemistry, National Research Centre, Dokki, Cairo, Egypt.
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22
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Kamalakannan P, Venkappayya D. Synthesis and characterization of cobalt and nickel chelates of 5-dimethylaminomethyl-2-thiouracil and their evaluation as antimicrobial and anticancer agents. J Inorg Biochem 2002; 90:22-37. [PMID: 12009252 DOI: 10.1016/s0162-0134(02)00413-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A new antimetabolite of adenine, viz. 5-dimethylaminomethyl-2-thiouracil, was synthesized using the Mannich reaction. Owing to the biological importance of metalloelements in many biological processes, especially metabolic processes, cobalt(II) and nickel(II) complexes were also synthesized and examined for their antimicrobial and anticancer activities. These new compounds were characterized structurally by various techniques ranging from micro-elemental analyses to spectral analyses. Cobalt(II) complexes were found to be four coordinate, among which the bromo, iodo, and nitrato complexes were polymeric. The nickel(II) isothiocyanato complex exhibited four-coordinate geometry and the remaining nickel(II) complexes were six coordinate. Thermodynamic and kinetic parameters evaluated based on TG/DSC suggested that the initial stage of thermal decomposition follows a diffusion-controlled mechanism and the final stage a chemically controlled mechanism. Antibacterial, antifungal, and antitumor studies undertaken for the above compounds indicated structure-activity relationships. These metalloderivatives were more active than the parent compound. The order of activity was influenced by the chelate geometry and thermal stability. Activity increased with a decrease in coordination number and increase in thermal lability.
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Affiliation(s)
- P Kamalakannan
- Department of Chemistry, Regional Engineering College, Tiruchirappalli 620 015, Tamilnadu, India
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23
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Macchia M, Barontini S, Bertini S, Di Bussolo V, Fogli S, Giovannetti E, Grossi E, Minutolo F, Danesi R. Design, synthesis, and characterization of the antitumor activity of novel ceramide analogues. J Med Chem 2001; 44:3994-4000. [PMID: 11689086 DOI: 10.1021/jm010947r] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A deficiency in apoptosis is one of the key events in the proliferation and resistance of malignant cells to antitumor agents; for these reasons, the search for apoptosis-inducing drugs represents a valuable approach for the development of novel anticancer therapies. In this study we report the first example of conformationally restrained analogues of ceramide (compounds 1-4), where the polar portion of the molecule has been replaced by a thiouracil (1, 3) or uracil (2, 4) ring. The evaluation of their biologic activity on CCRF-CEM human leukemia cells demonstrated that the most active was compound 1 followed by compound 2 (mean 50% inhibition of cell proliferation [IC(50)] 1.7 and 7.9 microM, respectively), while compounds 3 and 4 were inactive, as were uracil, thiouracil, and 5,6-dimethyluracil, the pyrimidine moieties of compounds 1-4. For comparison, the IC(50) of the reference substance, the cell-permeable C2-ceramide, was 31.6 microM. Compounds 1 and 2 and C2-ceramide were able to trigger apoptosis, as shown by the occurrence of DNA and nuclear fragmentation, and to release cytochrome c from treated cells. The treatment of female CD-1 nu/nu athymic mice bearing a WiDr human colon xenograft with the most active compound 1 at 2, 10, 50, and 200 mg/kg ip daily for 10 days resulted in an antitumor effect that was equivalent at 50 mg/kg or superior (200 mg/kg) to that of cyclophosphamide, 20 mg/kg ip daily, delivered on the same schedule, with markedly lower systemic toxicity. In conclusion, the present study demonstrates that the new ceramide analogues 1 and 2 are characterized by in vitro and in vivo antitumor activity and low toxicity.
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Affiliation(s)
- M Macchia
- Department of Pharmaceutical Sciences, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy.
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24
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Al Safarjalani ON, Zhou XJ, Naguib FN, Shi J, Schinazi RF, el Kouni MH. Enhancement of the bioavailability of oral uridine by coadministration of 5-(phenylthio)acyclouridine, a uridine phosphorylase inhibitor: implications for uridine rescue regimens in chemotherapy. Cancer Chemother Pharmacol 2001; 48:389-97. [PMID: 11761457 DOI: 10.1007/s002800100353] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE The purpose of this investigation was to evaluate the effectiveness of oral 5-(phenylthio)acyclouridine (PTAU) in improving the oral bioavailability of uridine. PTAU is a new potent and specific inhibitor of uridine phosphorylase (UrdPase, EC 2.4.2.3), the enzyme responsible for uridine catabolism. This compound was designed as a lipophilic inhibitor in order to facilitate its access to the liver and intestine, the main organs involved in uridine catabolism. PTAU is not toxic to mice and is fully absorbed after oral administration (100% oral bioavailability). METHODS PTAU was administered orally to mice alone or with uridine. The plasma levels of PTAU as well as those of uridine and its catabolite uracil were measured using HPLC, and pharmacokinetic analysis was performed. RESULTS Co-administration of PTAU with uridine elevated the concentration of plasma uridine in a dose-dependent manner over that resulting from the administration of the same dose of uridine alone, and reduced the clearance of uridine as well as the peak plasma concentration (Cmax) and area under the curve (AUC) of plasma uracil. Coadministration of PTAU at 30, 45 and 60 mg/kg improved the low oral bioavailability (7.7%) of uridine administered at 1320 mg/kg by 4.3-, 5.9- and 9.9-fold, respectively, and reduced the AUC of plasma uracil (1227.8 micromol x h/l) by 5.7-, 6.8- and 8.2-fold, respectively. Similar results were observed when PTAU was coadministered with lower doses of uridine. Oral PTAU at 30, 45 and 60 mg/kg improved the oral bioavailability of 330 mg/kg uridine by 1.8-, 2.6- and 2.8-fold, and that of 660 mg/kg uridine by 2.2-, 2.6- and 3.2-fold, respectively. CONCLUSION The effectiveness of PTAU in improving the oral bioavailability of uridine could be useful in the rescue or protection from host toxicities of various chemotherapeutic pyrimidine analogues as well as in the management of medical disorders that are remedied by administration of uridine.
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Affiliation(s)
- O N Al Safarjalani
- Department of Pharmacology and Toxicology, Comprehensive Cancer Center, University of Alabama at Birmingham, 35294, USA
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Abstract
This study determined the effects of thyroid hormone on the renal dopaminergic system. Surgical thyroidectomy (Tx) and treatment with 2-thiouracil (Thio) decreased renal cortex Na+/K+ ATPase activity and urinary volume. Tx also decreased urinary Na+ and urinary L-DOPA without changing urinary excretion of Dopamine (DA). Thio treatment decreased slightly urinary L-DOPA and Na+, but increased urinary excretion of DA. In both models of thyroid hormone deficiency, the ratio urinary DA/DOPA increased. Changes after Thio treatment were reversed after one month of drug withdrawal. Treatment with T3 via osmotic minipump increased Na+/K+ ATPase activity and urinary L-DOPA, did not change urinary DA, and increased the ratio DA/DOPA. To further analyze the effects of thyroid hormone deficiency, we administered selective DA1 (SCH-23390), DA2 (Sulpiride), and a non selective (Haloperidol) DA receptor antagonists to Thio treated and control animals. The DA1 antagonist decreased diuresis, natriuresis and urinary L-DOPA in control, but had no effect in Thio treated rats. Sulpiride had no effect in either group. The combination of SCH-23390 plus Sulpiride decreased urinary L-DOPA and urinary volume only in Thio treated animals. Haloperidol decreased urinary volume in Thio treated animals, but had no effect in controls. Our findings suggest that renal DA synthesis is to some extent dependent on thyroid hormone levels, and that the response of DA receptors is altered by thyroid hormone deficiency, indicating a role of this hormone in the regulation of the renal dopaminergic system.
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Affiliation(s)
- J A Del Compare
- Centro de Investigaciones Endocrinologicas, CONICET, Buenos Aires, Argentina.
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26
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Al Safarjalani ON, Zhou XJ, Naguib FN, Goudgaon NM, Schinazi RF, el Kouni MH. Modulation of the pharmacokinetics of endogenous plasma uridine by 5-(phenylthio)acyclouridine, a uridine phosphorylase inhibitor: implications for chemotherapy. Cancer Chemother Pharmacol 2001; 48:145-50. [PMID: 11565561 DOI: 10.1007/s002800100292] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE The purpose of this investigation was to evaluate the ability of oral PTAU, 5-(phenylthio)acyclouridine, to increase the concentration of endogenous plasma uridine. PTAU is a new potent and specific inhibitor of uridine phosphorylase (UrdPase, EC 2.4.2.3), the enzyme responsible for uridine catabolism. This compound was designed as a lipophilic inhibitor in order to facilitate its access to the liver and intestine, the main organs involved in uridine catabolism. METHODS PTAU was administered to mice orally and parenterally. The plasma levels of PTAU as well as those of uridine and its catabolite uracil were measured by HPLC, and pharmacokinetic analysis was performed. RESULTS PTAU was fully adsorbed after oral administration (over 100% oral bioavailability) and no PTAU metabolites were detected. PTAU administered orally had no apparent toxicity at doses up to 120 mg/kg per day for 5 days. Parenteral administration of PTAU at 30, 45 and 60 mg/kg increased the concentration of endogenous plasma uridine (1.8 +/- 0.2 microM) by approximately six-, seven-, and nine-fold, respectively. Plasma uridine concentration remained higher than control values until 8 h after PTAU administration. Similar results were obtained following oral administration of PTAU. The baseline concentrations of endogenous plasma uridine were increased by approximately six-, seven- and ten-fold by oral administration of PTAU at 30, 45 and 60 mg/kg, respectively, and remained higher than the controls until 8 h after PTAU administration. PTAU did not alter the concentration of endogenous plasma uracil. CONCLUSION The effectiveness of the PTAU in elevating and sustaining high plasma uridine concentrations may be useful in rescuing or protecting the host from toxicities of various chemotherapeutic pyrimidine analogues as well as in the management of medical disorders that respond to the administration of uridine.
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Affiliation(s)
- O N Al Safarjalani
- Department of Pharmacology and Toxicology, Comprehensive Cancer Center, University of Alabama at Birmingham, 35294, USA
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27
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Abstract
Two established antithyroid drugs, 6-propyl-2-thiouracil and 6-methyl-2-thiouracil, as well as S-methylthiouracil, are shown to be competitive inhibitors of nitric oxide synthase (NOS) (K(I) values ranging from 14 to 60 microM), with moderate selectivity for the neuronal isoform. Other thioureylene and thioamide-containing heterocyclic systems proved virtually ineffective as NOS inhibitors. Besides offering novel useful leads for inhibitor design as well as to probe the active site of neuronal NOS, the results of this study may have interesting implications in relation to the antithyroid activity of thiouracils and their possible neurological effects.
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Affiliation(s)
- A Palumbo
- Zoological Station "Anton Dohrn,", Naples, Villa Comunale, I-80121, Italy.
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28
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Huang X, Lee KJ, Riedel B, Zhang C, Lemanski LF, Walker JW. Thyroid hormone regulates slow skeletal troponin I gene inactivation in cardiac troponin I null mouse hearts. J Mol Cell Cardiol 2000; 32:2221-8. [PMID: 11112997 DOI: 10.1006/jmcc.2000.1249] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Two main troponin I genes, cardiac (cTnI) and slow skeletal (ssTnI), are expressed in the mammalian heart under the control of a developmentally regulated program. ssTnI is expressed first in embryonic and fetal heart, and is then downregulated by an unknown mechanism after birth. Unlike other contractile protein genes, ssTnI is not re-expressed during hypertrophy or end-stage heart failure in rats and humans. In the present study, we also show that ssTnI re-expression does not occur in hypertrophic mouse heart. To investigate ssTnI downregulation further, cTnI knockout mice were used to examine a possible role for thyroid hormone. Northern blot analysis of euthyroid animals showed a time-dependent loss of ssTnI mRNA that was similar for wild-type, heterozygous and homozygous cTnI mutant mice. In cTnI null mice made hyperthyroid by l -thyroxine, the duration of ssTnI expression assessed by both mRNA and protein content was abbreviated compared with the euthyroid group. Hyperthyroid cTnI null mice also died significantly earlier than euthyroids (postnatal day 14 v day 18). In cTnI null mice made hypothyroid by addition of phenylthiouracil to the drinking water, ssTnI expression was prolonged and mice survived until day 20 or 21. Overall, the results indicate that inactivation of the ssTnI gene occurs even in the absence of cTnI mRNA and protein indicating that these are not critical signals for ssTnI down regulation in the heart. In contrast, thyroid hormone influences the time course of ssTnI expression and the life span of cTnI null mice probably through a transcriptional regulation of ssTnI in the heart.
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Affiliation(s)
- X Huang
- Department of Medical Physiology, Texas A&M University System Health Science Center, College Station, TX 77843, USA.
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29
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Palumbo A, d'Ischia M, Cioffi FA. 2-thiouracil is a selective inhibitor of neuronal nitric oxide synthase antagonising tetrahydrobiopterin-dependent enzyme activation and dimerisation. FEBS Lett 2000; 485:109-12. [PMID: 11094150 DOI: 10.1016/s0014-5793(00)02194-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
2-thiouracil (TU), an established antithyroid drug and melanoma-seeker, was found to selectively inhibit neuronal nitric oxide synthase (nNOS) in a competitive manner (K(i)=20 microM), being inactive on the other NOS isoforms. The drug apparently interfered with the substrate- and tetrahydrobiopterin (BH(4))-binding to the enzyme. It caused a 60% inhibition of H(2)O(2) production in the absence of L-arginine and BH(4), and antagonised BH(4)-induced dimerisation of nNOS, but did not affect cytochrome c reduction. These results open new perspectives in the understanding of the antithyroid action of TU and provide a new lead structure for the development of selective nNOS inhibitors to elucidate the interdependence of the substrate and pteridine sites and to modulate pathologically aberrant NO formation.
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Affiliation(s)
- A Palumbo
- Zoological Station Anton Dohrn, Naples, Italy.
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30
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el Kouni MH, Goudgaon NM, Rafeeq M, Al Safarjalani ON, Schinazi RF, Naguib FN. 5-phenylthioacyclouridine: a potent and specific inhibitor of uridine phosphorylase. Biochem Pharmacol 2000; 60:851-6. [PMID: 10930540 DOI: 10.1016/s0006-2952(00)00410-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
5-Phenylthioacyclouridine (PTAU or 1-[(2-hydroxyethoxy)methyl]-5-phenylthiouracil) was synthesized as a highly specific and potent inhibitor of uridine phosphorylase (UrdPase, EC 2.4.2.3). PTAU has inhibition constant (K(is)) values of 248 and 353 nM towards UrdPase from mouse and human livers, respectively. PTAU was neither an inhibitor nor a substrate for thymidine phosphorylase (EC 2.4.2.4), uridine-cytidine kinase (EC 2. 7.1.48), thymidine kinase (EC 2.7.1.21), dihydrouracil dehydrogenase (EC 1.3.1.2), orotate phosphoribosyltransferase (EC 2.4.2.10), or orotidine 5'-monophosphate decarboxylase (EC 4.1.2.23), the enzymes that could utilize the substrate (uridine or thymidine) or products (uracil or thymine) of UrdPase. Different isomers of 5-tolylthiouracil also were synthesized and tested as inhibitors of UrdPase. The meta-substituted isomer was 3- to 4-fold more potent as an inhibitor of UrdPase than the para- or ortho-substituted isomers. These data indicate that the hydrophobic pocket in the active site of UrdPase adjacent to the 5-position of the pyrimidine ring can accommodate the meta-substituted 5-phenyluracils better than the other isomers, leading to improved inhibition. Therefore, it is anticipated that the potency of PTAU can be increased further by the addition of certain hydrophobic groups at the meta position of the phenyl ring. PTAU has potential usefulness in the therapy of cancer and AIDS as well as other pathological and physiological disorders that can be remedied by the administration of uridine.
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Affiliation(s)
- M H el Kouni
- Department of Pharmacology and Toxicology and Comprehensive Cancer Center, University of Alabama at Birmingham, 35294, USA.
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31
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Aliev G, Shi J, Perry G, Friedland RP, Lamanna JC. Decreased constitutive nitric oxide synthase, but increased inducible nitric oxide synthase and endothelin-1 immunoreactivity in aortic endothelial cells of donryu rats on a cholesterol-enriched diet. Anat Rec 2000; 260:16-25. [PMID: 10967532 DOI: 10.1002/1097-0185(20000901)260:1<16::aid-ar20>3.0.co;2-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The Donryu rat is resistant to a high cholesterol diet in that typical atheromatous lesions do not develop. Using electron microscopic immunocytochemical techniques, the effects of a CCT diet (4% cholesterol with 1% cholic acid and 0.5% thiouracil) on the distributions of neuronal, macrophage, and endothelial specific nitric oxide synthase (NOS I, NOS II, and NOS III) and endothelin-1 (ET-1) immunoreactivity were examined in the thoracic aortic intima. Atheromatous lesions were absent, but immunocytochemistry showed 1. 4+/-0.52% and 4.0+/-0.9% endothelial cells (EC) with positive staining for NOS I and NOS III, respectively, compared with 16.3+/-2. 5% and 88.6+/-2.48% in control Donryu rats. The CCT-supplemented diet induced expression of NOS II immunoreactivity in thoracic aortic intimal cells. EC, subendothelial macrophages, and smooth muscle cells (SMC) also showed high NOS II-positive staining. The percentage of NOS II-immunoreactive EC was 43+/-1.8%. In control groups, no NOS II immunoreactive cells were observed. The percentage of ET-1 immunopositive cells was also significantly increased by 9. 2+/-0.66% and 64.2+/-1.4% in control and CCT-fed groups, respectively. It is concluded that the administration of a high cholesterol diet in Donryu rats produces endothelial dysfunction associated with changes in the balance of the different isoforms of NOS and ET-1. Therefore, the increase in inducible NOS and ET-1 immunoreactivity seen during the cholesterol-enriched diet appears to be a compensatory reaction of aortic wall cells to the high cholesterol supplementation.
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Affiliation(s)
- G Aliev
- Laboratory of Electron Microscopy, Case Western Reserve University, Cleveland, Ohio 44106-4938, USA
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32
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Tohei A, Taya K, Watanabe G, Voogt JL. Hypothyroidism increases prolactin secretion and decreases the intromission threshold for induction of pseudopregnancy in adult female rats. Physiol Behav 2000; 69:391-7. [PMID: 10913776 DOI: 10.1016/s0031-9384(00)00224-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In order to understand the mechanism by which thyroid hormones alter prolactin (PRL) secretion, we investigated the role of tuberoinfundibular dopamine (TIDA) neurons and pituitary and hypothalamus vasoactive intestinal peptide (VIP) in thiouracil- (0. 03% in drinking water for 16 days) induced-hypothyroid adult female rats. The intromission threshold for induction of pseudopregnancy also was examined to evaluate the PRL response to coital stimulation in hypothyroid rats. Hypothyroidism in adult female rats did not affect TIDA neuronal activity as measured by tyrosine hydroxylase activity (DOPA accumulation 30 min after administration of m-hydroxybenzylhydrazine dihydrochloride, 100 mg/kg, i.p.) in the stalk-median eminence compared with that in euthyroid rats, whereas pituitary concentration of VIP was dramatically increased. Plasma concentration of PRL was higher at 1100 h of proestrus and estrus in hypothyroid rats as compared with that of euthyroid rats. The proportion of female rats exhibiting pseudopregnancy was higher in hypothyroid animals (100%) receiving seven intromissions than in euthyroid animals (43%). Administration of L-thyroxine in hypothyroid rats decreased the proportion of pseudopregnancy (40%) to the level of euthyroid animals. These results indicate that the increased level of pituitary VIP probably affects PRL secretion in a paracrine or autocrine manner and account for the hyperprolactinemia induced in hypothyroid female rats. No role for TIDA neurons in PRL elevation can be ascribed. A decrease in the intromission threshold for induction of pseudopregnancy might be due to increased levels of PRL in hypothyroid female rats.
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Affiliation(s)
- A Tohei
- Laboratory of Veterinary Physiology, Tokyo University of Agriculture and Technology, Fuchu, 183-8509, Tokyo, Japan.
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34
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Abstract
Changes in thyroid status affect metabolism not only directly, but influence it also by alterations in insulin secretion and action. Despite several investigations, these effects are, however, poorly characterised or even controversial. The aim of the studies was to investigate the effect of hyperthyreosis (HT) and hypothyreosis (HPT) on insulin binding by rat liver membranes. Some metabolic parameters reflecting insulin and thyroid hormones action were also determined. HT and HPT were developed by daily administration for 3 weeks of thyroxine (T (4) ) and thiouracil (TU), respectively. Experimental hyperthyreosis and hypothyreosis caused deep changes in metabolism. The greatest alterations were observed in body and thyroid glands weight, blood triiodothyronine (T (3) ), T (4), glucose, and insulin levels, liver glycogen amount and number of insulin receptors. HT reflected in rats in slower rate of growth and in smaller thyroid glands weight. In comparison to controls, T (4) concentration in HT was almost doubled and it was reduced by about 30% in HPT. Also, T(3), insulin and glucose levels in HT were heightened. Simultaneously, binding of insulin to liver membranes was elevated in HT and reduced in HPT. In HT the number of high affinity insulin receptors (HAIRs) and low affinity insulin receptors (LAIRs) was increased, whereas in HPT the amount of HAIRs was diminished. HT caused a drastic reduction of glycogen concentration in liver, but no changes were observed for muscle glycogen. Considering lipid metabolism, only free fatty acids (FFA) level in blood was changed (in HPT), but no differences were observed in serum concentration of triglycerides and cholesterol. Several metabolic changes observed in HT and HPT seem to be the dire ct consequence of alterations of thyroid hormone concentrations. These disturbances, together with the direct effect of HT or HPT on insulin secretion, binding and action lead, in turn, to changes in the other metabolic parameters. As a result of these disturbances the adaptive mechanisms appear. One of them is change in the number of insulin membrane receptors taking place even against the well known "down-regulation" theory.
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Affiliation(s)
- P Mackowiak
- Department of Animal Phsiology and Biochemistry, University of Agriculture, Poznan, Poland.
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35
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Roman I, Giurgea R. Thyroxin and thiouracyl influence upon some biochemical parameters in chicken thymuses. Rom J Physiol 1999; 36:97-101. [PMID: 11068610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Administration of L-thyroxin in a dose of 30 micrograms/chicken, i.m. and 2-thiouracyl in a dose of 0.3 mg/chicken, i.m. for an interval of 3 days, determined, at the thymus level, increases of total protein content in the Tu group, in parallel with decreases of the nitrogen of free amino acids level in the Tx group, increases of DNA content in the Tx group and an increase of the thymus weight in both groups. Modifications are due to the action of thyroxin, on the one hand, and on the other to the doses of antithyroid drug which determines a raise of T4 content in the plasma and the manifestation of activities specific to this hormone.
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Affiliation(s)
- I Roman
- Institute of Biological Research, Cluj-Napoca
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ESCOBAR DEL REY F, MORREALE DE ESCOBAR G, GARCIA GARCIA MD, MOURIZ GARCIA J. Increase of the rate of release of thyroidal iodine-131 and of circulating thyrotrophic activity at early stages of prophylthiouracil treatment in the rat. Nature 1998; 191:1171-3. [PMID: 13697337 DOI: 10.1038/1911171a0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Dramiński M, Turski K, Tateoka Y, Kimura T, Watanabe K, Kondo S, Ho IK, Yamamoto I. Synthesis and sedative-hypnotic effects of N3-allyl- and N1-allyl-5,6-substituted 2-thiouracil derivatives in mice. Chem Pharm Bull (Tokyo) 1998; 46:1370-3. [PMID: 9775432 DOI: 10.1248/cpb.46.1370] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Twenty four thiouracil derivatives, including N3-allyl- (19) and N1-allyl-2-thiouracil (20) were synthesized and their pharmacological effects [sedative-hypnotic activity (loss of righting reflex and spontaneous activity), convulsant activity, effect on pentobarbital (PB)-induced sleep and mortality] were evaluated in mice at doses of 320 mg/kg, i.p. and 2 mumol/mouse by intracerebroventricular (i.c.v.) injections, respectively. N3-Allyl-6-propyl-2-thiouracil (3), N3-allyl-5,6-dimethyl-2-thiouracil (10), N3-allyl-1,2,3,4,5,6,7,8,9-nonahydro-4-oxo-2-thiocyclohepta [d]pyrimidine (16) and N3-allyl-5-methyl-2-thiouracil (18) exhibited sedative-hypnotic activity, whereas N3-allyl-6-ethyl-5-methyl-2-thiouracil (11), N1-allyl-5-methyl-2-thiouracil (21), N1-allyl-1,2,3,4,5,6,7,8,9-nonahydro-4-oxo-2-thiocyclohepta[ d]pyrimidine (23) and N1-allyl-5,6-dimethyl-2-thiouracil (24) conversely displayed clonic- and/or tonic-convulsant seizures. N3-Allyl-6-propyl-2-thiouracil (3) and N3-allyl-5-methyl-2-thiouracil (18) decreased spontaneous activity. Other compounds examined were inactive, or only slightly active in the sedative-hypnotic assay even at high doses. Fifteen compounds (1-4, 7, 10, 11, 14-16, 18-21, and 23) significantly prolonged the PB-induced sleeping time. Interestingly, only N1-allyl-5,6-dimethyl-2-thiouracil (24) shortened the PB-induced sleeping time. These results showed that these thiouracils possessed many different effects such as sedative-hypnotic, anticonvulsant and/or convulsant, and that N3-allyl-5-methyl-2-thiouracil (18) and N1-allyl-5,6-dimethyl-2-thiouracil (24) had the most potent hypnotic activity and antagonistic effect against PB, respectively.
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Affiliation(s)
- M Dramiński
- Institute of Basic Sciences, Military School of Medicine, Lodz, Poland
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Rahman AA, Aal MT. Synthesis of (S)-1-(2',3'-dihydroxypropyl)-2-alkylthiouracils as new antiviral agents. Pharmazie 1998; 53:377-80. [PMID: 9675767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
2-Alkylthiouracils 1a-f have been prepared. Nucleoside coupling of 2 with sodium salt of 1a-f gave the corresponding dioxolane derivatives 3a-f which were treated with 80% acetic acid at reflux temperature to give (S)-1-(2',3'-dihydroxypropyl)-2-alkylthiouracil derivatives 4a-f. Treatment of 4d with 1 mol tosyl chloride gives the corresponding monotosylate 5. On the other hand, with 2 mol it gives the ditosylate 6. Treatment of 5 and/or 6 with sodium azide/dimethylformamide give 7 and 8 which could be reduced to the corresponding amino derivatives 9 and 10 by using triphenylphosphine/pyridine.
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Affiliation(s)
- A A Rahman
- Chemistry Department, Faculty of Science, Menoufia University, Shebin El-Koam, Egypt
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Abstract
Male copulatory behavior and the function of the hypothalamo-hypophysial-gonadal axis in hypothyroid male rats were investigated in the present study. Hypothyroidism was induced by thyroidectomy or thiouracil. In male copulatory behavior test, intromission latencies in hypothyroid rats were significantly longer than those in euthyroid rats and ejaculation frequencies were reduced in hypothyroid male rats compared to control rats without reduction of plasma concentrations of testosterone. These changes in copulatory behavior in hypothyroid male rats were restored to control levels by administration of T4 (5 micrograms/rat). Hypothyroidism decreased adrenal weights, and basal and peak concentrations of corticosterone during diurnal variation, whereas it increased peak concentrations of ACTH in adult male rats. These results indicate that hypothyroidism causes adrenal dysfunction directly and results in hypersecretion of ACTH. The adrenal disturbance observed in hypothyroid rats may affect male copulatory behavior.
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Affiliation(s)
- A Tohei
- Tokyo University of Agriculture and Technology, Japan
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Viglietto G, Romano A, Manzo G, Chiappetta G, Paoletti I, Califano D, Galati MG, Mauriello V, Bruni P, Lago CT, Fusco A, Persico MG. Upregulation of the angiogenic factors PlGF, VEGF and their receptors (Flt-1, Flk-1/KDR) by TSH in cultured thyrocytes and in the thyroid gland of thiouracil-fed rats suggest a TSH-dependent paracrine mechanism for goiter hypervascularization. Oncogene 1997; 15:2687-98. [PMID: 9400995 DOI: 10.1038/sj.onc.1201456] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Placenta growth factor (PlGF) and vascular endothelial growth factor (VEGF) represent two closely related angiogenic growth factors active as homodimers or heterodimers. Since goiters of the thyroid gland are extremely hypervascular, we investigated the expression of PlGF, VEGF and their receptors, Flt-1 and Flk-1/KDR, in a small panel of human goiters from patients with Graves's disease, in an animal model of thyroid goitrogenesis and in in vitro cultured thyroid cells. Here we report that the mRNA expression of PlGF, VEGF and their receptors is markedly enhanced in biopsies of goiters resected from Graves's patients. In vivo studies demonstrated that in the thyroid gland of thiouracil-fed rats, increased mRNA and protein expression of PIGF, VEGF, Flt-1 and Flk-1/KDR occurred subsequent to the rise in the serum thyroid stimulating hormone (TSH) levels and in parallel with thyroid capillary proliferation. In vitro studies confirmed the existence of such TSH-dependent paracrine communication between thyroid epithelial cells and endothelium since the conditioned medium collected from TSH-stimulated thyrocytes acquired mitogenic activity for human umbilical vein endothelial (HUVE) cells. Altogether, these data suggest that PlGF and VEGF, released by thyrocytes in response to the chronic activation of the TSH receptor pathway, may act through a paracrine mechanism on thyroid endothelium.
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MESH Headings
- Animals
- Antithyroid Agents/pharmacology
- Cells, Cultured
- Culture Media, Conditioned/pharmacology
- Endothelial Growth Factors/genetics
- Endothelial Growth Factors/metabolism
- Endothelial Growth Factors/pharmacology
- Endothelium, Vascular/cytology
- Goiter/physiopathology
- Graves Disease/metabolism
- Humans
- Lymphokines/drug effects
- Lymphokines/genetics
- Lymphokines/metabolism
- Lymphokines/pharmacology
- Neovascularization, Pathologic
- Placenta Growth Factor
- Pregnancy Proteins/drug effects
- Pregnancy Proteins/genetics
- Pregnancy Proteins/metabolism
- Protein Synthesis Inhibitors/pharmacology
- Proto-Oncogene Proteins/drug effects
- Proto-Oncogene Proteins/immunology
- Proto-Oncogene Proteins/metabolism
- RNA, Messenger
- Rats
- Rats, Inbred Strains
- Receptor Protein-Tyrosine Kinases/drug effects
- Receptor Protein-Tyrosine Kinases/immunology
- Receptor Protein-Tyrosine Kinases/metabolism
- Receptors, Growth Factor/drug effects
- Receptors, Growth Factor/immunology
- Receptors, Growth Factor/metabolism
- Receptors, Vascular Endothelial Growth Factor
- Thiouracil/pharmacology
- Thyroid Gland/cytology
- Thyroid Gland/drug effects
- Thyroid Gland/metabolism
- Thyrotropin/metabolism
- Thyrotropin/pharmacology
- Umbilical Veins/cytology
- Up-Regulation
- Vascular Endothelial Growth Factor A
- Vascular Endothelial Growth Factor Receptor-1
- Vascular Endothelial Growth Factors
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Affiliation(s)
- G Viglietto
- Istituto Nazionale dei Tumori Fondazione Senatore Pascale, Naples, Italy
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Abstract
The objective of the current study was to determine whether thyroid physiology may affect molting time in turkeys. Two trials using approximately 144 hens were conducted to elucidate thyroidal factors that limit the molting process. Thyroid hormones or a thyroid blocker (thiouracil) were given to the hens during a molt by supplementing the diet with thyroxine (T4), triiodothyronine (T3), or thiouracil. Supplementing with T4 reduced the number of days to return to egg production, whereas supplementing with thiouracil or T3 prolonged days to first egg. The observations support previous suggestions of separate functions for T3 and T4 during molting. As had been observed many times previously, the feeding of thiouracil delayed the molt but did not completely stop the molting process. The hens fed thiouracil returned to 50% egg production nearly 10 d after the control group, whereas T3 prolonged the return to 50% egg production nearly 1 wk later. The data indicate the endogenous low levels of T4, but not T3 in modern strains of turkeys may contribute to a relatively longer molting period of turkey breeder hens induced to molt out of season.
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Affiliation(s)
- W H Queen
- Department of Poultry Science, North Carolina State University, Releigh 27695-7608, USA
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Abstract
5-Ethyl-6-(1-naphthylmethyl)uracil and 5-ethyl-6-(1-naphthylmethyl)-2-thiouracil were alkylated to give, respectively. N-1 and S2, ethoxymethyl and methylthiomethyl uracil derivatives. 5-Ethyl-6-(1-naphthylmethyl)-2-thiouracil was also S2 alkylated with methyl bromoacetate. The products showed activity against HIV-1, and the N-1 alkylated derivatives were indeed highly active.
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Affiliation(s)
- K Danel
- Department of Chemistry, Odense University, Denmark
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Peebles ED, Miller EH, Boyle CR, Brake JD, Latour MA, Thaxton JP. Effects of consecutive thiouracil exposures in the juvenile and adult single comb White Leghorn chicken on body weight and reproductive performance. Poult Sci 1997; 76:236-43. [PMID: 9057201 DOI: 10.1093/ps/76.2.236] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The effects of consecutive exposures to dietary thiouracil (TU) in juvenile and adult Single Comb White Leghorn chickens on plasma thyroxine (T4) concentrations, egg production (EP), egg weight (EW), concentrations eggshell quality were determined. Thiouracil was provided in the feed at levels of 0, 0.1, or 0.2% (PTRT) from 0 to 6 wk of age and at levels of 0 or 0.1% (TRT) from 32 to 38 wk of age. Body weight gain was simulated but T4, EW, EP, and eggshell quality were generally reduced by 0.1% TU TRT. However, TU PTRT alleviated a latent depressing effect of TU TRT on BW after 38 wk of age. Thiouracil PTRT, particularly at the 0.2% level, induced significant decreases in EW but increased EP between 32 and 50 wk. The effects of early thyroid suppression in juveniles with TU PTRT on the subsequent reproduction of adults were primarily in response to a delay in the onset of sexual maturity, and not directly to prolonged responses in T4 or BW that extended into lay.
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Affiliation(s)
- E D Peebles
- Department of Poultry Science, Mississippi State University, Mississippi 39762, USA
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Komeda K, Iwamoto S, Kominami S, Ohnishi T. Induction of cell killing, mutation and umu gene expression by 6-mercaptopurine or 2-thiouracil with UVA irradiation. Photochem Photobiol 1997; 65:115-8. [PMID: 9066290 DOI: 10.1111/j.1751-1097.1997.tb01885.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
When Escherichia coli cells were irradiated by UVA in the presence of 6-mercaptopurine (6-MP) or 2-thiouracil (S2Ura), two kinds of repair-deficient strains of recA- and uvrA- were killed more efficiently than the parental wild-type strain having normal repair capacities. In addition, these agents with UVA exposure greatly induced the incidence of mutations in the uvrA- strain as compared with the wild-type strain but not the recA- strain. Furthermore, the induction of expression of umuDC genes was investigated in two Salmonella typhimurium strains, TA1535 and TA1538, carrying a pSK1002 plasmid. In these systems, it is easy to measure beta-galactosidase activities for the induced activities of SOS responses. These agents with UVA exposure also induced expression of the umuDC genes. These results suggest that 6-MP and S2Ura with UVA induce DNA damage which is repairable by the excision repair mechanism.
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Affiliation(s)
- K Komeda
- Department of Pharmacology, Nara Medical University, Japan
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Kirby JD, Mankar MV, Hardesty D, Kreider DL. Effects of transient prepubertal 6-N-propyl-2-thiouracil treatment on testis development and function in the domestic fowl. Biol Reprod 1996; 55:910-6. [PMID: 8879508 DOI: 10.1095/biolreprod55.4.910] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
It has been well established that thyroid hormones play an important role in regulating the onset of puberty and reproductive function in birds. In mammals it has been shown that transient hypothyroidism induced with the reversible goitrogen 6-N-propyl-2-thiouracil (PTU) can result in tremendous increases in testis size and sperm production and that the timing of hypothyroidism must correspond to the period of Sertoli cell proliferation. As the period of Sertoli cell proliferation is not precisely known in the fowl, an experiment was conducted to determine whether chicken testes have a similar window of sensitivity to PTU treatment. Broiler breeder male chicks (Peterson) were placed in floor pens at one day of age and reared according to the breeder's management guide for the entire 28-wk duration (controls) or up to the point of dietary treatment with PTU (0.1% w:w) for 6 wk that began at 2-wk intervals (2-8, 4-10, 6-12, 8-14, and 10-16 wk of age); after treatment, birds were returned to feed restriction and photostimulated at 20 wk of age. Birds were bled and killed, and testes were collected at 4-wk intervals. At 28 wk, one testis was fixed for histological examination and one was immediately placed in liquid N2 for sperm counts. Treatment with PTU from 6 to 12 wk of age resulted in a 96% increase in mean testis weight at 28 wk of age (treated 39.3 +/- 4.1 g per testis vs. control 20.0 +/- 1.6 g per testis). These testes exhibited normal morphology and increased relative sperm production. Treatment with PTU from either 8 to 14 or 10 to 16 wk of age resulted in approximately a 35% increase in testis mass at 28 wk of age relative to the control value (27.2 +/- 2.0 g and 27.7 +/- 3.6 g vs. 20.0 +/- 1.6 g per testis, respectively). However, both of these groups clearly demonstrated precocious puberty and abnormal spermatogenesis. These results suggest that appropriately timed PTU treatment may result in permanent increases in testis size and sperm production in the domestic fowl.
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Affiliation(s)
- J D Kirby
- Department of Poultry Science, University of Arkansas, Fayetteville 72701, USA
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Veronikis IE, Alex S, Fang SL, Wright G, Wu SY, Chanoine JP, Emerson CH, Braverman LE. Serum iodothyronine concentrations in intestinally decontaminated rats treated with a 5'-deiodinase type I inhibitor 6-anilino-2-thiouracil. Eur J Endocrinol 1996; 134:519-23. [PMID: 8640307 DOI: 10.1530/eje.0.1340519] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Enteric bacteria have been postulated to have a role in thyroid economy by promoting the hydrolysis of thyroid hormone conjugates of biliary origin, thus permitting the absorption and recycling of thyroxine (T4) and triiodothyronine (T3). An enterohepatic circulation of T3 might be more pronounced under conditions in which type I iodothyronine deiodinase activity (5'D-I) is inhibited, because this augments the accumulation of T3 sulfate conjugates in bile. This potential of increased gut reabsorption of T3 might explain, at least in part, the failure of serum T3 values to decrease appreciably when marked reductions in peripheral 5'D-I activity are induced by selenium deficiency or 6-anilino-2-thiouracil (ATU) administration. Thus, studies were performed to determine the effect of intestinal decontamination, in the absence and in the presence of 5'D-I inhibition, on plasma T4 and T3 concentrations. Groups of adult male rats received either enteric antibiotics or no antibiotics for 12 days and then, in half of the rats in each group, treatment for 10 days with ATU, a 5'D-I inhibitor that does not affect thyroid hormone synthesis. The activity of intestinal arylsulfatase and arylsulfotransferase, enzymes that catalyze hydrolysis of thyroid hormone conjugates, was reduced markedly by approximately 87% in rats that received antibiotics, regardless of whether or not they also received ATU. The ATU treatment markedly inhibited liver 5'D-I activity in antibiotic-treated as well as in non-antibiotic-treated rats (control = 399 +/- 32 U/mg protein (mean +/- SEM); ATU = 152 +/- 17: antibiotics = 351 +/- 29; antibiotics + ATU = 130 +/- 10; p < 0.01) and significantly increased plasma T4 and T3 sulfate (T4S, T3S) concentrations (control: T4S = 2.8 +/- 0.4 and T3S = 6.7 +/- 1.3 ng/dl; ATU: T4S = 6.2 +/- 1.4 and T3S = 10.6 +/- 2.1 ng/dl; antibiotics: T4S = 1.8 +/- 0.2 and T3S = 3.6 +/- 1.0 ng/dl; antibiotics + ATU: T4S = 6.8 +/- 0.7 and T3S = 9.7 +/- 1.8 ng/dl; p < 0.05). The ATU treatment was associated with a significant increase in plasma T4 and rT3 concentrations but did not affect plasma T3 concentrations, and intestinal decontamination did not alter these ATU-associated effects on circulating thyroid hormones. These results suggest that anaerobic enteric bacteria in the rat do not have an important role in recycling of thyroid hormones, either under normal conditions or in circumstances where 5'D-I activity is markedly reduced, and that increased gut absorption of T3 from T3S cannot explain the near-normal serum T3 values found when peripheral 5'D-I activity is markedly decreased.
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Affiliation(s)
- I E Veronikis
- Department of Medicine, University of Massachusetts Medical School, Worcester 01655, USA
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Abstract
In this paper, the activity of horseradish peroxidase was further determined in the presence of several uracil derivatives. The rate of guaiacol peroxidation decreases in presence of 2-thiouracil and of 6-n-propyl-2-thiouracil, but is not changed by 6-n-propyluracil nor uracil. Thus, thiouracils inhibit horseradish peroxidase in a noncompetitive form. The binding of 6-n-propyl-2-thiouracil, 2-thiouracil, 6-n-propyluracil and uracil with horseradish peroxidase shows difference spectra due to changes in the environment of heme group in peroxidase. Then, the binding sites for these uracil derivatives are in an hydrophobic pocket at the heme periphery of peroxidase. The lesser binding rates were for uracil and propyluracil, which did not inhibit the peroxidase activity. These results point to the thiol group in uracils as responsible for the inhibition of peroxidase activity through interaction with an allosteric binding site, in peroxidase heme environment.
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Affiliation(s)
- A M Zatón
- Departamento de Bioquímica y Biología Molecular, Universidad del País Vasco, Facultad de Farmacia, Vitoria-Gasteiz, España
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Sato K, Yamazaki K, Shizume K, Kanaji Y, Obara T, Ohsumi K, Demura H, Yamaguchi S, Shibuya M. Stimulation by thyroid-stimulating hormone and Grave's immunoglobulin G of vascular endothelial growth factor mRNA expression in human thyroid follicles in vitro and flt mRNA expression in the rat thyroid in vivo. J Clin Invest 1995; 96:1295-302. [PMID: 7657804 PMCID: PMC185751 DOI: 10.1172/jci118164] [Citation(s) in RCA: 121] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
To elucidate the pathogenesis of thyroid gland hypervascularity in patients with Graves' disease, we studied the expression of mRNAs for vascular endothelial growth factor (VEGF) and its receptor, Flt family, using human thyroid follicles in vitro and thiouracil-fed rats in vivo. Human thyroid follicles, cultured in the absence of endothelial cells, secreted de novo-synthesized thyroid hormone in response to thyroid-stimulating hormone (TSH) and Graves' IgG. The thyroid follicles produced VEGF mRNA but not flt-1 mRNA. The expression of VEGF mRNA was enhanced by insulin, tumor-promoting phorbol ester, calcium ionophore, dibutyryl cAMP, TSH, and Graves' IgG. When rats were fed thiouracil for 4 wk, their serum levels of TSH were increased at day 3. VEGF mRNA was also increased on day 3, accompanied by an increase in flt family (flt-1 and KDR/ flk-1) mRNA expression. These in vitro and in vivo findings suggest that VEGF is produced by thyroid follicles in response to stimulators of TSH receptors, via the protein kinase A and C pathways. VEGF, a secretable angiogenesis factor, subsequently stimulates Flt receptors on endothelial cells in a paracrine manner, leading to their proliferation and producing hypervascularity of the thyroid gland, as seen in patients with Graves' disease.
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Affiliation(s)
- K Sato
- Department of Medicine, Tokyo Women's Medical College, Japan
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