Monoamines and Protein Intake: Are Control Mechanisms Designed to Monitor a Threshold Intake or a Set Point?

Femstrom, Madelyn H.

doi:10.1111/j.1753-4887.2001.tb05502.x

Cited by 12 publications

(10 citation statements)

References 27 publications

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“…10, 2009 and maintaining a positive nitrogen balance, 4 and is the precursor of dopa, dopamine, thyroxin, and epinephrine hormone or neurotransmitters. 5,6 The absence of Tyr could cause albinism and alkaptonuria, while a high L-tyrosine concentration in culture medium results in increased sister chromatid exchange. Thus, the analytical determination of Tyr is a pharmacological necessity.…”

Section: Introductionmentioning

confidence: 99%

A sensitive simultaneous determination of epinephrine and tyrosine using an iron(III) doped zeolite-modified carbon paste electrode

Babaei¹,

Mirzakhani²,

Khalilzadeh³

2009

J. Braz. Chem. Soc.

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Um eletrodo de pasta de carbono modificado com zeólitas e dopado com ferro(III) foi usado como um sensor eletroquímico de alta sensibilidade e seletividade para a determinação simultânea de pequenas quantidades de compostos biologicamente importantes como epinefrina (Ep) e tirosina (Tyr). Os resultados da voltametria de pulso diferencial (DPV) usando este eletrodo modificado mostra duas ondas anódicas bem traçadas para a oxidação da Ep e da Tyr, as quais tornam possíveis a determinação simultanêa destes compostos. A faixa linear de 0,9 a 216 mmol L -1 para a Ep em uma concentração fixa de 30 mmol L -1 Tyr em solução tampão fosfato, pH 3,0 foi obtida das medidas de DPV usando este eletrodo, com um coeficiente de correlação de 0,9998 e limite de quantificação igual a 0,44 mmol L -1 . A linearidade obtida para a Tyr na presença de 30 mmol L -1 de Ep, foi de 1,2 a 90 mmol L -1 com um coeficiente de correlação de 0,9989 e limite de quantificação de 0,32 mmol L -1 . O eletrodo modificado apresentou uma boa reprodutibilidade (RSD< 2.5%), baixo limite de quantificação (sub-micromolar) e alta sensibilidade para a detecção de ambos Ep e Tyr com uma elevada estabilidade em sua resposta voltamétrica. O desempenho analítico deste sensor tem sido avaliado para a detecção de epinefrina e tirosina em soro humano e em amostras farmacêuticas com resultados satisfatórios.A Zeolite modified carbon paste electrode doped with iron(III) was used as a highly sensitive and selective electrochemical sensor for simultaneous determination of minor amounts of epinephrine (Ep) and tyrosine (Tyr) as the biologically important compounds. The results of differential pulse voltammetry (DPV) using this modified electrode show two well-resolved anodic waves for the oxidation of Ep and Tyr ,which makes it possible for simultaneous determination of both compounds. A linear range from 0.9 to 216 mmol L -1 for Ep at a constant concentration of 30 mmol L -1 Tyr in buffered solution (phosphate buffer, pH 3.0) was obtained from DPV measurement using this electrode with a correlation coefficient of 0.9998 and a detection limit of 0.44 mmol L -1 . The linear range, which is obtained for Tyr in the presence of 30 mmol L -1 Ep, was in the range from 1.2 to 90 µmol L -1 with a correlation coefficient of 0.9989 and a detection limit of 0.32 mmol L -1 . The modified electrode had good reproducibility (RSD < 2.5%), low detection limit (sub-micromolar) and high sensitivity for the detection of both Ep and Tyr with a very high stability in its voltammetric response. The analytical performance of this sensor has been evaluated for detection of Ep and Tyr in human serum and in a pharmaceutical sample with satisfactory results.Keywords: Epinephrine, tyrosine, Fe(III) doped zeolite, modified carbon paste electrode IntroductionEpinephrine (Ep), Scheme 1 (a), often called adrenaline, is one of the most important neurotransmitters in mammalian central nervous systems, existing in the nervous tissue and body fluid, and controlling the nervous system in the performance of ...

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Section: Introductionmentioning

confidence: 99%

A sensitive simultaneous determination of epinephrine and tyrosine using an iron(III) doped zeolite-modified carbon paste electrode

Babaei¹,

Mirzakhani²,

Khalilzadeh³

2009

J. Braz. Chem. Soc.

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“…The range of 2% to 10% protein intake brackets the adult rat's protein requirement (5%-6%) [52], suggesting that this dietary-amino acid-neurochemical relationship might function as a signal to brain regarding the adequacy of protein intake. This hypothesis seems compatible with the observation that rats in the wild (ie, freely selecting a natural diet) ingest a level of protein modestly above their requirement [2], similar to humans [53]. A similar suggestion might also be made for monkeys.…”

Section: Discussionmentioning

confidence: 53%

“…These changes have been linked to rapid alterations in their brain concentrations and, in some cases, to neurotransmitter products derived from them. Such relationships have been described for tryptophan (TRP) and its transmitter product, serotonin (5HT), tyrosine (TYR) and the catecholamine transmitters that derive from it, and histidine (HIS) and histamine [1][2][3][4][5]. Such neurotransmitter modifications are of particular physiologic interest when they can be linked to the control of food intake, as they suggest possible pathways by which the brain might sense and modify the appetite for energy and specific macronutrients, such as protein (eg, Fernstrom and Fernstrom [2]).…”

Section: Introductionmentioning

confidence: 97%

Cerebrospinal fluid concentrations of large neutral and basic amino acids in Macaca mulatta: diurnal variations and responses to chronic changes in dietary protein intake

2009

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“…TR and AA are the most imperative fundamental moieties for the living organisms. TR is one of the conditional aromatic amino acid, which is found in numerous foodstuffs; also it is a precursor for the hormones, neurotransmitters, pigments and some needful proteins . TR reveals many applications in the human body such as improvement of mental efficiency, maintenance of positive nitrogen balance, photosynthesis, normalization of high blood pressure, curing of Parkinson's disease and Alzheimer's disease ,.…”

Section: Introductionmentioning

confidence: 99%

Sensitive and Selective Electrochemical Resolution of Tyrosine with Ascorbic Acid through the Development of Electropolymerized Alizarin Sodium Sulfonate Modified Carbon Nanotube Paste Electrodes

et al. 2019

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An approachable and a selective electrocatalytic investigation of tyrosine (TR) with ascorbic acid (AA) in phosphate buffer solution (PBS) was done using a sensitive Poly Alizarin sodium sulfonate modified Carbon nanotube paste electrode (PASSMCNTPE). The morphological and elemental studies on PASSMCNTPE and bare carbon nanotube paste electrode (BCNTPE) were resolute through field emission scanning electron microscopy (FESEM) and energy dispersive X‐ray spectroscopy (EDX). The PASSMCNTPE shows excellent sensitivity, selectivity, stability, repeatability, and reproducibility for the electrochemical characterization of TR through cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The prepared sensor provides an elevated current response towards TR as compared to the BCNTPE. A plot of the anodic peak current of TR and the concentration of TR was obtained linearly in the range 1.4×10−4 M to 2×10−4 M with the limit of detection (LOD) 7.8×10−7 M and the limit of quantification (LOQ) 26×10−7 M respectively. The equipped sensor was also helpful for the quantitative and qualitative analysis of TR moiety in a pharmaceutical drug as a real sample.

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Monoamines and Protein Intake: Are Control Mechanisms Designed to Monitor a Threshold Intake or a Set Point?

Cited by 12 publications

References 27 publications

A sensitive simultaneous determination of epinephrine and tyrosine using an iron(III) doped zeolite-modified carbon paste electrode

A sensitive simultaneous determination of epinephrine and tyrosine using an iron(III) doped zeolite-modified carbon paste electrode

Cerebrospinal fluid concentrations of large neutral and basic amino acids in Macaca mulatta: diurnal variations and responses to chronic changes in dietary protein intake

Sensitive and Selective Electrochemical Resolution of Tyrosine with Ascorbic Acid through the Development of Electropolymerized Alizarin Sodium Sulfonate Modified Carbon Nanotube Paste Electrodes

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