Tetrahydrobiopterin Bh4
Mostrando 1-12 de 30 artigos, teses e dissertações.
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1. Metabolic Control in Patients With Phenylketonuria Pre- and Post-Sapropterin Loading Test
Abstract In Portugal, tetrahydrobiopterin (BH4)-responsive patients with phenylketonuria (PKU) are identified using a loading test (LT). Phenylalanine/natural protein (Phe/NP) intake is increased to elevate blood Phe prior to the LT. In a longitudinal retrospective study, the impact of Phe/NP titration post-LT in 58 patients (19.6 + 8.2 years) with PKU durin
J. inborn errors metab. screen.. Publicado em: 28/02/2019
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2. No diabetes mellitus o chá verde melhora o desacoplamento da áxido nítrico sintase renal por restabelecer os valores de tetrahidrobiopterina = : Uncoupling endothelial nitric oxid synthase is ameliorated by green tea in experimental diabetes mellitus by reestablishing tetrahydrobiopterin levels / Uncoupling endothelial nitric oxid synthase is ameliorated by green tea in experimental diabetes mellitus by reestablishing tetrahydrobiopterin levels
No diabetes mellitus (DM), o estresse oxidativo e a redução do óxido nítrico (NO) contribuem para a patogênese da nefropatia diabética. O desacoplamento da NO sintase endotelial (eNOS) faz com que essa sintase produza superóxido ao invés de NO. O objetivo do presente estudo foi investigar o potencial do chá verde (CV) na melhora do desacoplamento da
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 14/06/2012
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3. Hiperfenilalaninemia por deficiência de fenilalanina hidroxilase : avaliação da responsividade ao BH4 em pacientes acompanhados no Serviço de Genética Médica do HCPA e que apresentam controle metabólico adequado
Introdução: Estudos recentes, utilizando vários protocolos, têm demonstrado que pacientes com Hiperfenilalaninemia por deficiência de fenilalanina hidroxilase (HPA-PAH) podem apresentar redução das concentrações plasmáticas de fenilalanina (Phe) mediante a administração de tetrahidrobiopterina (BH4). Objetivo: Determinar, em uma amostra de pacien
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2011
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4. Hiperfenilalaninemia por deficiência de fenilalanina hidroxilase : identificação de indivíduos responsivos à administração de tetrahidrobiopterina por via oral
Introdução: A Hiperfenilalaninemia por deficiência de fenilalanina hidroxilase (HPAPAH) é um erro inato do metabolismo no qual ocorre aumento dos níveis séricos de fenilalanina (Phe). Estudos recentes, realizados em várias populações, demonstraram que pacientes com HPA-PAH podem apresentar redução das concentrações plasmáticas de Phe mediante a
Publicado em: 2010
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5. Nitric oxide: a major determinant of mast cell phenotype and function
Mast cells (MC) are important in the numerous physiological processes of homeostasis and disease. Most notably, MC are critical effectors in the development and exacerbation of allergic disorders. Nitric oxide (NO) is a diatomic radical produced by nitric oxide synthase (NOS), and has pluripotent cell signaling and cytotoxic properties. NO can influence many
Memórias do Instituto Oswaldo Cruz. Publicado em: 2005-03
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6. Participação do oxido nitrico no desenvolvimento da encefalomielite alergica experimental em ratos
Nitric oxide (NO) is a free radical endogenously synthetised by oxidation of one of the guanidinum nitrogen atoms of the aminoacid L-arginine by molecular oxygen. This biosynthesis is catalised by a family of enzimes generically known as nitric oxide synthases (NOS), which can be inhibited by structural analogs of L-arginine having substituent groups at the
Publicado em: 2001
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7. "7-tetrahydrobiopterin," a naturally occurring analogue of tetrahydrobiopterin, is a cofactor for and a potential inhibitor of the aromatic amino acid hydroxylases.
The ability of 2-amino-4-hydroxy-7-[dihydroxylpropyl-(L-erythro)-5,6,7,8-tetrahyd ropterin] ("7-tetrahydrobiopterin" or 7-BH4) to substitute for the natural cofactor tetrahydrobiopterin (BH4) has been studied in vitro in the reactions of the three mammalian aromatic amino acid hydroxylases. With rat liver phenylalanine hydroxylase, the apparent Km for 7-BH4
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8. Correction of kinetic and stability defects by tetrahydrobiopterin in phenylketonuria patients with certain phenylalanine hydroxylase mutations
Phenylketonuria patients harboring a subset of phenylalanine hydroxylase (PAH) mutations have recently shown normalization of blood phenylalanine levels upon oral administration of the PAH cofactor tetrahydrobiopterin [(6R)-l-erythro-5,6,7,8-tetrahydrobiopterin (BH4)]. Several hypotheses have been put forward to explain BH4 responsiveness, but the molecular
National Academy of Sciences.
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9. Biosynthesis of tetrahydrobiopterin by de novo and salvage pathways in adrenal medulla extracts, mammalian cell cultures, and rat brain in vivo.
Mammalian cells and tissues were found to have two pathways for the biosynthesis of tetrahydrobiopterin (BH4): (i) the conversion of GTP to BH4 by a methotrexate-insensitive de novo pathway, and (ii) the conversion of sepiapterin to BH4 by a pterin salvage pathway dependent on dihydrofolate reductase (5,6,7,8-tetrahydrofolate: NADP+ oxidoreductase, EC 1.5.1.
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10. Coordinate regulation of tetrahydrobiopterin turnover and phenylalanine hydroxylase activity in rat liver cells.
This work had two purposes: (i) to determine in vivo whether liver phenylalanine hydroxylase (PAH) is regulated by its substrates phenylalanine and tetrahydrobiopterin (BH4) as studies with purified enzyme suggest and (ii) to investigate in vivo the relationship between PAH activity and BH4 turnover. We found there are two BH4 pools in hepatocytes, one that
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11. Tetrahydrobiopterin-dependent preservation of nitric oxide–mediated endothelial function in diabetes by targeted transgenic GTP–cyclohydrolase I overexpression
Increased production of reactive oxygen species and loss of endothelial NO bioactivity are key features of vascular disease states such as diabetes mellitus. Tetrahydrobiopterin (BH4) is a required cofactor for eNOS activity; pharmacologic studies suggest that BH4 may mediate some of the adverse effects of diabetes on eNOS function. We have now investigated
American Society for Clinical Investigation.
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12. Tetrahydrobiopterin, the cofactor for aromatic amino acid hydroxylases, is synthesized by and regulates proliferation of erythroid cells.
The only known role for 6(R)-5,6,7,8-tetrahydrobiopterin (BH4) is as the cofactor for the aromatic amino acid hydroxylases. However, BH4 has been shown to be synthesized by cells that do not contain any hydroxylase activity, suggesting that it may have still undiscovered functions. Our finding of much higher levels of BH4 and GTP cyclohydrolase, the first en